# Copyright 2001-2016 by Vinay Sajip. All Rights Reserved.
#
# Permission to use, copy, modify, and distribute this software and its
# documentation for any purpose and without fee is hereby granted,
# provided that the above copyright notice appear in all copies and that
# both that copyright notice and this permission notice appear in
# supporting documentation, and that the name of Vinay Sajip
# not be used in advertising or publicity pertaining to distribution
# of the software without specific, written prior permission.
# VINAY SAJIP DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
# ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
# VINAY SAJIP BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
# ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
# IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. """
Logging package for Python. Based on PEP 282 and comments thereto in
comp.lang.python. Copyright (C) 2001-2016 Vinay Sajip. All Rights Reserved. To use, simply 'import logging' and log away!
""" import sys, os, time, io, traceback, warnings, weakref, collections from string import Template __all__ = ['BASIC_FORMAT', 'BufferingFormatter', 'CRITICAL', 'DEBUG', 'ERROR',
'FATAL', 'FileHandler', 'Filter', 'Formatter', 'Handler', 'INFO',
'LogRecord', 'Logger', 'LoggerAdapter', 'NOTSET', 'NullHandler',
'StreamHandler', 'WARN', 'WARNING', 'addLevelName', 'basicConfig',
'captureWarnings', 'critical', 'debug', 'disable', 'error',
'exception', 'fatal', 'getLevelName', 'getLogger', 'getLoggerClass',
'info', 'log', 'makeLogRecord', 'setLoggerClass', 'shutdown',
'warn', 'warning', 'getLogRecordFactory', 'setLogRecordFactory',
'lastResort', 'raiseExceptions'] try:
import threading
except ImportError: #pragma: no cover
threading = None __author__ = "Vinay Sajip <vinay_sajip@red-dove.com>"
__status__ = "production"
# The following module attributes are no longer updated.
__version__ = "0.5.1.2"
__date__ = "07 February 2010" #---------------------------------------------------------------------------
# Miscellaneous module data
#--------------------------------------------------------------------------- #
#_startTime is used as the base when calculating the relative time of events
#
_startTime = time.time() #
#raiseExceptions is used to see if exceptions during handling should be
#propagated
#
raiseExceptions = True #
# If you don't want threading information in the log, set this to zero
#
logThreads = True #
# If you don't want multiprocessing information in the log, set this to zero
#
logMultiprocessing = True #
# If you don't want process information in the log, set this to zero
#
logProcesses = True #---------------------------------------------------------------------------
# Level related stuff
#---------------------------------------------------------------------------
#
# Default levels and level names, these can be replaced with any positive set
# of values having corresponding names. There is a pseudo-level, NOTSET, which
# is only really there as a lower limit for user-defined levels. Handlers and
# loggers are initialized with NOTSET so that they will log all messages, even
# at user-defined levels.
# CRITICAL = 50
FATAL = CRITICAL
ERROR = 40
WARNING = 30
WARN = WARNING
INFO = 20
DEBUG = 10
NOTSET = 0 _levelToName = {
CRITICAL: 'CRITICAL',
ERROR: 'ERROR',
WARNING: 'WARNING',
INFO: 'INFO',
DEBUG: 'DEBUG',
NOTSET: 'NOTSET',
}
_nameToLevel = {
'CRITICAL': CRITICAL,
'FATAL': FATAL,
'ERROR': ERROR,
'WARN': WARNING,
'WARNING': WARNING,
'INFO': INFO,
'DEBUG': DEBUG,
'NOTSET': NOTSET,
} def getLevelName(level):
"""
Return the textual representation of logging level 'level'. If the level is one of the predefined levels (CRITICAL, ERROR, WARNING,
INFO, DEBUG) then you get the corresponding string. If you have
associated levels with names using addLevelName then the name you have
associated with 'level' is returned. If a numeric value corresponding to one of the defined levels is passed
in, the corresponding string representation is returned. Otherwise, the string "Level %s" % level is returned.
"""
# See Issues #22386, #27937 and #29220 for why it's this way
result = _levelToName.get(level)
if result is not None:
return result
result = _nameToLevel.get(level)
if result is not None:
return result
return "Level %s" % level def addLevelName(level, levelName):
"""
Associate 'levelName' with 'level'. This is used when converting levels to text during message formatting.
"""
_acquireLock()
try: #unlikely to cause an exception, but you never know...
_levelToName[level] = levelName
_nameToLevel[levelName] = level
finally:
_releaseLock() if hasattr(sys, '_getframe'):
currentframe = lambda: sys._getframe(3)
else: #pragma: no cover
def currentframe():
"""Return the frame object for the caller's stack frame."""
try:
raise Exception
except Exception:
return sys.exc_info()[2].tb_frame.f_back #
# _srcfile is used when walking the stack to check when we've got the first
# caller stack frame, by skipping frames whose filename is that of this
# module's source. It therefore should contain the filename of this module's
# source file.
#
# Ordinarily we would use __file__ for this, but frozen modules don't always
# have __file__ set, for some reason (see Issue #21736). Thus, we get the
# filename from a handy code object from a function defined in this module.
# (There's no particular reason for picking addLevelName.)
# _srcfile = os.path.normcase(addLevelName.__code__.co_filename) # _srcfile is only used in conjunction with sys._getframe().
# To provide compatibility with older versions of Python, set _srcfile
# to None if _getframe() is not available; this value will prevent
# findCaller() from being called. You can also do this if you want to avoid
# the overhead of fetching caller information, even when _getframe() is
# available.
#if not hasattr(sys, '_getframe'):
# _srcfile = None def _checkLevel(level):
if isinstance(level, int):
rv = level
elif str(level) == level:
if level not in _nameToLevel:
raise ValueError("Unknown level: %r" % level)
rv = _nameToLevel[level]
else:
raise TypeError("Level not an integer or a valid string: %r" % level)
return rv #---------------------------------------------------------------------------
# Thread-related stuff
#--------------------------------------------------------------------------- #
#_lock is used to serialize access to shared data structures in this module.
#This needs to be an RLock because fileConfig() creates and configures
#Handlers, and so might arbitrary user threads. Since Handler code updates the
#shared dictionary _handlers, it needs to acquire the lock. But if configuring,
#the lock would already have been acquired - so we need an RLock.
#The same argument applies to Loggers and Manager.loggerDict.
#
if threading:
_lock = threading.RLock()
else: #pragma: no cover
_lock = None def _acquireLock():
"""
Acquire the module-level lock for serializing access to shared data. This should be released with _releaseLock().
"""
if _lock:
_lock.acquire() def _releaseLock():
"""
Release the module-level lock acquired by calling _acquireLock().
"""
if _lock:
_lock.release() #---------------------------------------------------------------------------
# The logging record
#--------------------------------------------------------------------------- class LogRecord(object):
"""
A LogRecord instance represents an event being logged. LogRecord instances are created every time something is logged. They
contain all the information pertinent to the event being logged. The
main information passed in is in msg and args, which are combined
using str(msg) % args to create the message field of the record. The
record also includes information such as when the record was created,
the source line where the logging call was made, and any exception
information to be logged.
"""
def __init__(self, name, level, pathname, lineno,
msg, args, exc_info, func=None, sinfo=None, **kwargs):
"""
Initialize a logging record with interesting information.
"""
ct = time.time()
self.name = name
self.msg = msg
#
# The following statement allows passing of a dictionary as a sole
# argument, so that you can do something like
# logging.debug("a %(a)d b %(b)s", {'a':1, 'b':2})
# Suggested by Stefan Behnel.
# Note that without the test for args[0], we get a problem because
# during formatting, we test to see if the arg is present using
# 'if self.args:'. If the event being logged is e.g. 'Value is %d'
# and if the passed arg fails 'if self.args:' then no formatting
# is done. For example, logger.warning('Value is %d', 0) would log
# 'Value is %d' instead of 'Value is 0'.
# For the use case of passing a dictionary, this should not be a
# problem.
# Issue #21172: a request was made to relax the isinstance check
# to hasattr(args[0], '__getitem__'). However, the docs on string
# formatting still seem to suggest a mapping object is required.
# Thus, while not removing the isinstance check, it does now look
# for collections.Mapping rather than, as before, dict.
if (args and len(args) == 1 and isinstance(args[0], collections.Mapping)
and args[0]):
args = args[0]
self.args = args
self.levelname = getLevelName(level)
self.levelno = level
self.pathname = pathname
try:
self.filename = os.path.basename(pathname)
self.module = os.path.splitext(self.filename)[0]
except (TypeError, ValueError, AttributeError):
self.filename = pathname
self.module = "Unknown module"
self.exc_info = exc_info
self.exc_text = None # used to cache the traceback text
self.stack_info = sinfo
self.lineno = lineno
self.funcName = func
self.created = ct
self.msecs = (ct - int(ct)) * 1000
self.relativeCreated = (self.created - _startTime) * 1000
if logThreads and threading:
self.thread = threading.get_ident()
self.threadName = threading.current_thread().name
else: # pragma: no cover
self.thread = None
self.threadName = None
if not logMultiprocessing: # pragma: no cover
self.processName = None
else:
self.processName = 'MainProcess'
mp = sys.modules.get('multiprocessing')
if mp is not None:
# Errors may occur if multiprocessing has not finished loading
# yet - e.g. if a custom import hook causes third-party code
# to run when multiprocessing calls import. See issue 8200
# for an example
try:
self.processName = mp.current_process().name
except Exception: #pragma: no cover
pass
if logProcesses and hasattr(os, 'getpid'):
self.process = os.getpid()
else:
self.process = None def __str__(self):
return '<LogRecord: %s, %s, %s, %s, "%s">'%(self.name, self.levelno,
self.pathname, self.lineno, self.msg) __repr__ = __str__ def getMessage(self):
"""
Return the message for this LogRecord. Return the message for this LogRecord after merging any user-supplied
arguments with the message.
"""
msg = str(self.msg)
if self.args:
msg = msg % self.args
return msg #
# Determine which class to use when instantiating log records.
#
_logRecordFactory = LogRecord def setLogRecordFactory(factory):
"""
Set the factory to be used when instantiating a log record. :param factory: A callable which will be called to instantiate
a log record.
"""
global _logRecordFactory
_logRecordFactory = factory def getLogRecordFactory():
"""
Return the factory to be used when instantiating a log record.
""" return _logRecordFactory def makeLogRecord(dict):
"""
Make a LogRecord whose attributes are defined by the specified dictionary,
This function is useful for converting a logging event received over
a socket connection (which is sent as a dictionary) into a LogRecord
instance.
"""
rv = _logRecordFactory(None, None, "", 0, "", (), None, None)
rv.__dict__.update(dict)
return rv #---------------------------------------------------------------------------
# Formatter classes and functions
#--------------------------------------------------------------------------- class PercentStyle(object): default_format = '%(message)s'
asctime_format = '%(asctime)s'
asctime_search = '%(asctime)' def __init__(self, fmt):
self._fmt = fmt or self.default_format def usesTime(self):
return self._fmt.find(self.asctime_search) >= 0 def format(self, record):
return self._fmt % record.__dict__ class StrFormatStyle(PercentStyle):
default_format = '{message}'
asctime_format = '{asctime}'
asctime_search = '{asctime' def format(self, record):
return self._fmt.format(**record.__dict__) class StringTemplateStyle(PercentStyle):
default_format = '${message}'
asctime_format = '${asctime}'
asctime_search = '${asctime}' def __init__(self, fmt):
self._fmt = fmt or self.default_format
self._tpl = Template(self._fmt) def usesTime(self):
fmt = self._fmt
return fmt.find('$asctime') >= 0 or fmt.find(self.asctime_format) >= 0 def format(self, record):
return self._tpl.substitute(**record.__dict__) BASIC_FORMAT = "%(levelname)s:%(name)s:%(message)s" _STYLES = {
'%': (PercentStyle, BASIC_FORMAT),
'{': (StrFormatStyle, '{levelname}:{name}:{message}'),
'$': (StringTemplateStyle, '${levelname}:${name}:${message}'),
} class Formatter(object):
"""
Formatter instances are used to convert a LogRecord to text. Formatters need to know how a LogRecord is constructed. They are
responsible for converting a LogRecord to (usually) a string which can
be interpreted by either a human or an external system. The base Formatter
allows a formatting string to be specified. If none is supplied, the
default value of "%s(message)" is used. The Formatter can be initialized with a format string which makes use of
knowledge of the LogRecord attributes - e.g. the default value mentioned
above makes use of the fact that the user's message and arguments are pre-
formatted into a LogRecord's message attribute. Currently, the useful
attributes in a LogRecord are described by: %(name)s Name of the logger (logging channel)
%(levelno)s Numeric logging level for the message (DEBUG, INFO,
WARNING, ERROR, CRITICAL)
%(levelname)s Text logging level for the message ("DEBUG", "INFO",
"WARNING", "ERROR", "CRITICAL")
%(pathname)s Full pathname of the source file where the logging
call was issued (if available)
%(filename)s Filename portion of pathname
%(module)s Module (name portion of filename)
%(lineno)d Source line number where the logging call was issued
(if available)
%(funcName)s Function name
%(created)f Time when the LogRecord was created (time.time()
return value)
%(asctime)s Textual time when the LogRecord was created
%(msecs)d Millisecond portion of the creation time
%(relativeCreated)d Time in milliseconds when the LogRecord was created,
relative to the time the logging module was loaded
(typically at application startup time)
%(thread)d Thread ID (if available)
%(threadName)s Thread name (if available)
%(process)d Process ID (if available)
%(message)s The result of record.getMessage(), computed just as
the record is emitted
""" converter = time.localtime def __init__(self, fmt=None, datefmt=None, style='%'):
"""
Initialize the formatter with specified format strings. Initialize the formatter either with the specified format string, or a
default as described above. Allow for specialized date formatting with
the optional datefmt argument (if omitted, you get the ISO8601 format). Use a style parameter of '%', '{' or '$' to specify that you want to
use one of %-formatting, :meth:`str.format` (``{}``) formatting or
:class:`string.Template` formatting in your format string. .. versionchanged:: 3.2
Added the ``style`` parameter.
"""
if style not in _STYLES:
raise ValueError('Style must be one of: %s' % ','.join(
_STYLES.keys()))
self._style = _STYLES[style][0](fmt)
self._fmt = self._style._fmt
self.datefmt = datefmt default_time_format = '%Y-%m-%d %H:%M:%S'
default_msec_format = '%s,%03d' def formatTime(self, record, datefmt=None):
"""
Return the creation time of the specified LogRecord as formatted text. This method should be called from format() by a formatter which
wants to make use of a formatted time. This method can be overridden
in formatters to provide for any specific requirement, but the
basic behaviour is as follows: if datefmt (a string) is specified,
it is used with time.strftime() to format the creation time of the
record. Otherwise, the ISO8601 format is used. The resulting
string is returned. This function uses a user-configurable function
to convert the creation time to a tuple. By default, time.localtime()
is used; to change this for a particular formatter instance, set the
'converter' attribute to a function with the same signature as
time.localtime() or time.gmtime(). To change it for all formatters,
for example if you want all logging times to be shown in GMT,
set the 'converter' attribute in the Formatter class.
"""
ct = self.converter(record.created)
if datefmt:
s = time.strftime(datefmt, ct)
else:
t = time.strftime(self.default_time_format, ct)
s = self.default_msec_format % (t, record.msecs)
return s def formatException(self, ei):
"""
Format and return the specified exception information as a string. This default implementation just uses
traceback.print_exception()
"""
sio = io.StringIO()
tb = ei[2]
# See issues #9427, #1553375. Commented out for now.
#if getattr(self, 'fullstack', False):
# traceback.print_stack(tb.tb_frame.f_back, file=sio)
traceback.print_exception(ei[0], ei[1], tb, None, sio)
s = sio.getvalue()
sio.close()
if s[-1:] == "\n":
s = s[:-1]
return s def usesTime(self):
"""
Check if the format uses the creation time of the record.
"""
return self._style.usesTime() def formatMessage(self, record):
return self._style.format(record) def formatStack(self, stack_info):
"""
This method is provided as an extension point for specialized
formatting of stack information. The input data is a string as returned from a call to
:func:`traceback.print_stack`, but with the last trailing newline
removed. The base implementation just returns the value passed in.
"""
return stack_info def format(self, record):
"""
Format the specified record as text. The record's attribute dictionary is used as the operand to a
string formatting operation which yields the returned string.
Before formatting the dictionary, a couple of preparatory steps
are carried out. The message attribute of the record is computed
using LogRecord.getMessage(). If the formatting string uses the
time (as determined by a call to usesTime(), formatTime() is
called to format the event time. If there is exception information,
it is formatted using formatException() and appended to the message.
"""
record.message = record.getMessage()
if self.usesTime():
record.asctime = self.formatTime(record, self.datefmt)
s = self.formatMessage(record)
if record.exc_info:
# Cache the traceback text to avoid converting it multiple times
# (it's constant anyway)
if not record.exc_text:
record.exc_text = self.formatException(record.exc_info)
if record.exc_text:
if s[-1:] != "\n":
s = s + "\n"
s = s + record.exc_text
if record.stack_info:
if s[-1:] != "\n":
s = s + "\n"
s = s + self.formatStack(record.stack_info)
return s #
# The default formatter to use when no other is specified
#
_defaultFormatter = Formatter() class BufferingFormatter(object):
"""
A formatter suitable for formatting a number of records.
"""
def __init__(self, linefmt=None):
"""
Optionally specify a formatter which will be used to format each
individual record.
"""
if linefmt:
self.linefmt = linefmt
else:
self.linefmt = _defaultFormatter def formatHeader(self, records):
"""
Return the header string for the specified records.
"""
return "" def formatFooter(self, records):
"""
Return the footer string for the specified records.
"""
return "" def format(self, records):
"""
Format the specified records and return the result as a string.
"""
rv = ""
if len(records) > 0:
rv = rv + self.formatHeader(records)
for record in records:
rv = rv + self.linefmt.format(record)
rv = rv + self.formatFooter(records)
return rv #---------------------------------------------------------------------------
# Filter classes and functions
#--------------------------------------------------------------------------- class Filter(object):
"""
Filter instances are used to perform arbitrary filtering of LogRecords. Loggers and Handlers can optionally use Filter instances to filter
records as desired. The base filter class only allows events which are
below a certain point in the logger hierarchy. For example, a filter
initialized with "A.B" will allow events logged by loggers "A.B",
"A.B.C", "A.B.C.D", "A.B.D" etc. but not "A.BB", "B.A.B" etc. If
initialized with the empty string, all events are passed.
"""
def __init__(self, name=''):
"""
Initialize a filter. Initialize with the name of the logger which, together with its
children, will have its events allowed through the filter. If no
name is specified, allow every event.
"""
self.name = name
self.nlen = len(name) def filter(self, record):
"""
Determine if the specified record is to be logged. Is the specified record to be logged? Returns 0 for no, nonzero for
yes. If deemed appropriate, the record may be modified in-place.
"""
if self.nlen == 0:
return True
elif self.name == record.name:
return True
elif record.name.find(self.name, 0, self.nlen) != 0:
return False
return (record.name[self.nlen] == ".") class Filterer(object):
"""
A base class for loggers and handlers which allows them to share
common code.
"""
def __init__(self):
"""
Initialize the list of filters to be an empty list.
"""
self.filters = [] def addFilter(self, filter):
"""
Add the specified filter to this handler.
"""
if not (filter in self.filters):
self.filters.append(filter) def removeFilter(self, filter):
"""
Remove the specified filter from this handler.
"""
if filter in self.filters:
self.filters.remove(filter) def filter(self, record):
"""
Determine if a record is loggable by consulting all the filters. The default is to allow the record to be logged; any filter can veto
this and the record is then dropped. Returns a zero value if a record
is to be dropped, else non-zero. .. versionchanged:: 3.2 Allow filters to be just callables.
"""
rv = True
for f in self.filters:
if hasattr(f, 'filter'):
result = f.filter(record)
else:
result = f(record) # assume callable - will raise if not
if not result:
rv = False
break
return rv #---------------------------------------------------------------------------
# Handler classes and functions
#--------------------------------------------------------------------------- _handlers = weakref.WeakValueDictionary() #map of handler names to handlers
_handlerList = [] # added to allow handlers to be removed in reverse of order initialized def _removeHandlerRef(wr):
"""
Remove a handler reference from the internal cleanup list.
"""
# This function can be called during module teardown, when globals are
# set to None. It can also be called from another thread. So we need to
# pre-emptively grab the necessary globals and check if they're None,
# to prevent race conditions and failures during interpreter shutdown.
acquire, release, handlers = _acquireLock, _releaseLock, _handlerList
if acquire and release and handlers:
acquire()
try:
if wr in handlers:
handlers.remove(wr)
finally:
release() def _addHandlerRef(handler):
"""
Add a handler to the internal cleanup list using a weak reference.
"""
_acquireLock()
try:
_handlerList.append(weakref.ref(handler, _removeHandlerRef))
finally:
_releaseLock() class Handler(Filterer):
"""
Handler instances dispatch logging events to specific destinations. The base handler class. Acts as a placeholder which defines the Handler
interface. Handlers can optionally use Formatter instances to format
records as desired. By default, no formatter is specified; in this case,
the 'raw' message as determined by record.message is logged.
"""
def __init__(self, level=NOTSET):
"""
Initializes the instance - basically setting the formatter to None
and the filter list to empty.
"""
Filterer.__init__(self)
self._name = None
self.level = _checkLevel(level)
self.formatter = None
# Add the handler to the global _handlerList (for cleanup on shutdown)
_addHandlerRef(self)
self.createLock() def get_name(self):
return self._name def set_name(self, name):
_acquireLock()
try:
if self._name in _handlers:
del _handlers[self._name]
self._name = name
if name:
_handlers[name] = self
finally:
_releaseLock() name = property(get_name, set_name) def createLock(self):
"""
Acquire a thread lock for serializing access to the underlying I/O.
"""
if threading:
self.lock = threading.RLock()
else: #pragma: no cover
self.lock = None def acquire(self):
"""
Acquire the I/O thread lock.
"""
if self.lock:
self.lock.acquire() def release(self):
"""
Release the I/O thread lock.
"""
if self.lock:
self.lock.release() def setLevel(self, level):
"""
Set the logging level of this handler. level must be an int or a str.
"""
self.level = _checkLevel(level) def format(self, record):
"""
Format the specified record. If a formatter is set, use it. Otherwise, use the default formatter
for the module.
"""
if self.formatter:
fmt = self.formatter
else:
fmt = _defaultFormatter
return fmt.format(record) def emit(self, record):
"""
Do whatever it takes to actually log the specified logging record. This version is intended to be implemented by subclasses and so
raises a NotImplementedError.
"""
raise NotImplementedError('emit must be implemented '
'by Handler subclasses') def handle(self, record):
"""
Conditionally emit the specified logging record. Emission depends on filters which may have been added to the handler.
Wrap the actual emission of the record with acquisition/release of
the I/O thread lock. Returns whether the filter passed the record for
emission.
"""
rv = self.filter(record)
if rv:
self.acquire()
try:
self.emit(record)
finally:
self.release()
return rv def setFormatter(self, fmt):
"""
Set the formatter for this handler.
"""
self.formatter = fmt def flush(self):
"""
Ensure all logging output has been flushed. This version does nothing and is intended to be implemented by
subclasses.
"""
pass def close(self):
"""
Tidy up any resources used by the handler. This version removes the handler from an internal map of handlers,
_handlers, which is used for handler lookup by name. Subclasses
should ensure that this gets called from overridden close()
methods.
"""
#get the module data lock, as we're updating a shared structure.
_acquireLock()
try: #unlikely to raise an exception, but you never know...
if self._name and self._name in _handlers:
del _handlers[self._name]
finally:
_releaseLock() def handleError(self, record):
"""
Handle errors which occur during an emit() call. This method should be called from handlers when an exception is
encountered during an emit() call. If raiseExceptions is false,
exceptions get silently ignored. This is what is mostly wanted
for a logging system - most users will not care about errors in
the logging system, they are more interested in application errors.
You could, however, replace this with a custom handler if you wish.
The record which was being processed is passed in to this method.
"""
if raiseExceptions and sys.stderr: # see issue 13807
t, v, tb = sys.exc_info()
try:
sys.stderr.write('--- Logging error ---\n')
traceback.print_exception(t, v, tb, None, sys.stderr)
sys.stderr.write('Call stack:\n')
# Walk the stack frame up until we're out of logging,
# so as to print the calling context.
frame = tb.tb_frame
while (frame and os.path.dirname(frame.f_code.co_filename) ==
__path__[0]):
frame = frame.f_back
if frame:
traceback.print_stack(frame, file=sys.stderr)
else:
# couldn't find the right stack frame, for some reason
sys.stderr.write('Logged from file %s, line %s\n' % (
record.filename, record.lineno))
# Issue 18671: output logging message and arguments
try:
sys.stderr.write('Message: %r\n'
'Arguments: %s\n' % (record.msg,
record.args))
except Exception:
sys.stderr.write('Unable to print the message and arguments'
' - possible formatting error.\nUse the'
' traceback above to help find the error.\n'
)
except OSError: #pragma: no cover
pass # see issue 5971
finally:
del t, v, tb def __repr__(self):
level = getLevelName(self.level)
return '<%s (%s)>' % (self.__class__.__name__, level) class StreamHandler(Handler):
"""
A handler class which writes logging records, appropriately formatted,
to a stream. Note that this class does not close the stream, as
sys.stdout or sys.stderr may be used.
""" terminator = '\n' def __init__(self, stream=None):
"""
Initialize the handler. If stream is not specified, sys.stderr is used.
"""
Handler.__init__(self)
if stream is None:
stream = sys.stderr
self.stream = stream def flush(self):
"""
Flushes the stream.
"""
self.acquire()
try:
if self.stream and hasattr(self.stream, "flush"):
self.stream.flush()
finally:
self.release() def emit(self, record):
"""
Emit a record. If a formatter is specified, it is used to format the record.
The record is then written to the stream with a trailing newline. If
exception information is present, it is formatted using
traceback.print_exception and appended to the stream. If the stream
has an 'encoding' attribute, it is used to determine how to do the
output to the stream.
"""
try:
msg = self.format(record)
stream = self.stream
stream.write(msg)
stream.write(self.terminator)
self.flush()
except Exception:
self.handleError(record) def __repr__(self):
level = getLevelName(self.level)
name = getattr(self.stream, 'name', '')
if name:
name += ' '
return '<%s %s(%s)>' % (self.__class__.__name__, name, level) class FileHandler(StreamHandler):
"""
A handler class which writes formatted logging records to disk files.
"""
def __init__(self, filename, mode='a', encoding=None, delay=False):
"""
Open the specified file and use it as the stream for logging.
"""
# Issue #27493: add support for Path objects to be passed in
filename = os.fspath(filename)
#keep the absolute path, otherwise derived classes which use this
#may come a cropper when the current directory changes
self.baseFilename = os.path.abspath(filename)
self.mode = mode
self.encoding = encoding
self.delay = delay
if delay:
#We don't open the stream, but we still need to call the
#Handler constructor to set level, formatter, lock etc.
Handler.__init__(self)
self.stream = None
else:
StreamHandler.__init__(self, self._open()) def close(self):
"""
Closes the stream.
"""
self.acquire()
try:
try:
if self.stream:
try:
self.flush()
finally:
stream = self.stream
self.stream = None
if hasattr(stream, "close"):
stream.close()
finally:
# Issue #19523: call unconditionally to
# prevent a handler leak when delay is set
StreamHandler.close(self)
finally:
self.release() def _open(self):
"""
Open the current base file with the (original) mode and encoding.
Return the resulting stream.
"""
return open(self.baseFilename, self.mode, encoding=self.encoding) def emit(self, record):
"""
Emit a record. If the stream was not opened because 'delay' was specified in the
constructor, open it before calling the superclass's emit.
"""
if self.stream is None:
self.stream = self._open()
StreamHandler.emit(self, record) def __repr__(self):
level = getLevelName(self.level)
return '<%s %s (%s)>' % (self.__class__.__name__, self.baseFilename, level) class _StderrHandler(StreamHandler):
"""
This class is like a StreamHandler using sys.stderr, but always uses
whatever sys.stderr is currently set to rather than the value of
sys.stderr at handler construction time.
"""
def __init__(self, level=NOTSET):
"""
Initialize the handler.
"""
Handler.__init__(self, level) @property
def stream(self):
return sys.stderr _defaultLastResort = _StderrHandler(WARNING)
lastResort = _defaultLastResort #---------------------------------------------------------------------------
# Manager classes and functions
#--------------------------------------------------------------------------- class PlaceHolder(object):
"""
PlaceHolder instances are used in the Manager logger hierarchy to take
the place of nodes for which no loggers have been defined. This class is
intended for internal use only and not as part of the public API.
"""
def __init__(self, alogger):
"""
Initialize with the specified logger being a child of this placeholder.
"""
self.loggerMap = { alogger : None } def append(self, alogger):
"""
Add the specified logger as a child of this placeholder.
"""
if alogger not in self.loggerMap:
self.loggerMap[alogger] = None #
# Determine which class to use when instantiating loggers.
# def setLoggerClass(klass):
"""
Set the class to be used when instantiating a logger. The class should
define __init__() such that only a name argument is required, and the
__init__() should call Logger.__init__()
"""
if klass != Logger:
if not issubclass(klass, Logger):
raise TypeError("logger not derived from logging.Logger: "
+ klass.__name__)
global _loggerClass
_loggerClass = klass def getLoggerClass():
"""
Return the class to be used when instantiating a logger.
"""
return _loggerClass class Manager(object):
"""
There is [under normal circumstances] just one Manager instance, which
holds the hierarchy of loggers.
"""
def __init__(self, rootnode):
"""
Initialize the manager with the root node of the logger hierarchy.
"""
self.root = rootnode
self.disable = 0
self.emittedNoHandlerWarning = False
self.loggerDict = {}
self.loggerClass = None
self.logRecordFactory = None def getLogger(self, name):
"""
Get a logger with the specified name (channel name), creating it
if it doesn't yet exist. This name is a dot-separated hierarchical
name, such as "a", "a.b", "a.b.c" or similar. If a PlaceHolder existed for the specified name [i.e. the logger
didn't exist but a child of it did], replace it with the created
logger and fix up the parent/child references which pointed to the
placeholder to now point to the logger.
"""
rv = None
if not isinstance(name, str):
raise TypeError('A logger name must be a string')
_acquireLock()
try:
if name in self.loggerDict:
rv = self.loggerDict[name]
if isinstance(rv, PlaceHolder):
ph = rv
rv = (self.loggerClass or _loggerClass)(name)
rv.manager = self
self.loggerDict[name] = rv
self._fixupChildren(ph, rv)
self._fixupParents(rv)
else:
rv = (self.loggerClass or _loggerClass)(name)
rv.manager = self
self.loggerDict[name] = rv
self._fixupParents(rv)
finally:
_releaseLock()
return rv def setLoggerClass(self, klass):
"""
Set the class to be used when instantiating a logger with this Manager.
"""
if klass != Logger:
if not issubclass(klass, Logger):
raise TypeError("logger not derived from logging.Logger: "
+ klass.__name__)
self.loggerClass = klass def setLogRecordFactory(self, factory):
"""
Set the factory to be used when instantiating a log record with this
Manager.
"""
self.logRecordFactory = factory def _fixupParents(self, alogger):
"""
Ensure that there are either loggers or placeholders all the way
from the specified logger to the root of the logger hierarchy.
"""
name = alogger.name
i = name.rfind(".")
rv = None
while (i > 0) and not rv:
substr = name[:i]
if substr not in self.loggerDict:
self.loggerDict[substr] = PlaceHolder(alogger)
else:
obj = self.loggerDict[substr]
if isinstance(obj, Logger):
rv = obj
else:
assert isinstance(obj, PlaceHolder)
obj.append(alogger)
i = name.rfind(".", 0, i - 1)
if not rv:
rv = self.root
alogger.parent = rv def _fixupChildren(self, ph, alogger):
"""
Ensure that children of the placeholder ph are connected to the
specified logger.
"""
name = alogger.name
namelen = len(name)
for c in ph.loggerMap.keys():
#The if means ... if not c.parent.name.startswith(nm)
if c.parent.name[:namelen] != name:
alogger.parent = c.parent
c.parent = alogger #---------------------------------------------------------------------------
# Logger classes and functions
#--------------------------------------------------------------------------- class Logger(Filterer):
"""
Instances of the Logger class represent a single logging channel. A
"logging channel" indicates an area of an application. Exactly how an
"area" is defined is up to the application developer. Since an
application can have any number of areas, logging channels are identified
by a unique string. Application areas can be nested (e.g. an area
of "input processing" might include sub-areas "read CSV files", "read
XLS files" and "read Gnumeric files"). To cater for this natural nesting,
channel names are organized into a namespace hierarchy where levels are
separated by periods, much like the Java or Python package namespace. So
in the instance given above, channel names might be "input" for the upper
level, and "input.csv", "input.xls" and "input.gnu" for the sub-levels.
There is no arbitrary limit to the depth of nesting.
"""
def __init__(self, name, level=NOTSET):
"""
Initialize the logger with a name and an optional level.
"""
Filterer.__init__(self)
self.name = name
self.level = _checkLevel(level)
self.parent = None
self.propagate = True
self.handlers = []
self.disabled = False def setLevel(self, level):
"""
Set the logging level of this logger. level must be an int or a str.
"""
self.level = _checkLevel(level) def debug(self, msg, *args, **kwargs):
"""
Log 'msg % args' with severity 'DEBUG'. To pass exception information, use the keyword argument exc_info with
a true value, e.g. logger.debug("Houston, we have a %s", "thorny problem", exc_info=1)
"""
if self.isEnabledFor(DEBUG):
self._log(DEBUG, msg, args, **kwargs) def info(self, msg, *args, **kwargs):
"""
Log 'msg % args' with severity 'INFO'. To pass exception information, use the keyword argument exc_info with
a true value, e.g. logger.info("Houston, we have a %s", "interesting problem", exc_info=1)
"""
if self.isEnabledFor(INFO):
self._log(INFO, msg, args, **kwargs) def warning(self, msg, *args, **kwargs):
"""
Log 'msg % args' with severity 'WARNING'. To pass exception information, use the keyword argument exc_info with
a true value, e.g. logger.warning("Houston, we have a %s", "bit of a problem", exc_info=1)
"""
if self.isEnabledFor(WARNING):
self._log(WARNING, msg, args, **kwargs) def warn(self, msg, *args, **kwargs):
warnings.warn("The 'warn' method is deprecated, "
"use 'warning' instead", DeprecationWarning, 2)
self.warning(msg, *args, **kwargs) def error(self, msg, *args, **kwargs):
"""
Log 'msg % args' with severity 'ERROR'. To pass exception information, use the keyword argument exc_info with
a true value, e.g. logger.error("Houston, we have a %s", "major problem", exc_info=1)
"""
if self.isEnabledFor(ERROR):
self._log(ERROR, msg, args, **kwargs) def exception(self, msg, *args, exc_info=True, **kwargs):
"""
Convenience method for logging an ERROR with exception information.
"""
self.error(msg, *args, exc_info=exc_info, **kwargs) def critical(self, msg, *args, **kwargs):
"""
Log 'msg % args' with severity 'CRITICAL'. To pass exception information, use the keyword argument exc_info with
a true value, e.g. logger.critical("Houston, we have a %s", "major disaster", exc_info=1)
"""
if self.isEnabledFor(CRITICAL):
self._log(CRITICAL, msg, args, **kwargs) fatal = critical def log(self, level, msg, *args, **kwargs):
"""
Log 'msg % args' with the integer severity 'level'. To pass exception information, use the keyword argument exc_info with
a true value, e.g. logger.log(level, "We have a %s", "mysterious problem", exc_info=1)
"""
if not isinstance(level, int):
if raiseExceptions:
raise TypeError("level must be an integer")
else:
return
if self.isEnabledFor(level):
self._log(level, msg, args, **kwargs) def findCaller(self, stack_info=False):
"""
Find the stack frame of the caller so that we can note the source
file name, line number and function name.
"""
f = currentframe()
#On some versions of IronPython, currentframe() returns None if
#IronPython isn't run with -X:Frames.
if f is not None:
f = f.f_back
rv = "(unknown file)", 0, "(unknown function)", None
while hasattr(f, "f_code"):
co = f.f_code
filename = os.path.normcase(co.co_filename)
if filename == _srcfile:
f = f.f_back
continue
sinfo = None
if stack_info:
sio = io.StringIO()
sio.write('Stack (most recent call last):\n')
traceback.print_stack(f, file=sio)
sinfo = sio.getvalue()
if sinfo[-1] == '\n':
sinfo = sinfo[:-1]
sio.close()
rv = (co.co_filename, f.f_lineno, co.co_name, sinfo)
break
return rv def makeRecord(self, name, level, fn, lno, msg, args, exc_info,
func=None, extra=None, sinfo=None):
"""
A factory method which can be overridden in subclasses to create
specialized LogRecords.
"""
rv = _logRecordFactory(name, level, fn, lno, msg, args, exc_info, func,
sinfo)
if extra is not None:
for key in extra:
if (key in ["message", "asctime"]) or (key in rv.__dict__):
raise KeyError("Attempt to overwrite %r in LogRecord" % key)
rv.__dict__[key] = extra[key]
return rv def _log(self, level, msg, args, exc_info=None, extra=None, stack_info=False):
"""
Low-level logging routine which creates a LogRecord and then calls
all the handlers of this logger to handle the record.
"""
sinfo = None
if _srcfile:
#IronPython doesn't track Python frames, so findCaller raises an
#exception on some versions of IronPython. We trap it here so that
#IronPython can use logging.
try:
fn, lno, func, sinfo = self.findCaller(stack_info)
except ValueError: # pragma: no cover
fn, lno, func = "(unknown file)", 0, "(unknown function)"
else: # pragma: no cover
fn, lno, func = "(unknown file)", 0, "(unknown function)"
if exc_info:
if isinstance(exc_info, BaseException):
exc_info = (type(exc_info), exc_info, exc_info.__traceback__)
elif not isinstance(exc_info, tuple):
exc_info = sys.exc_info()
record = self.makeRecord(self.name, level, fn, lno, msg, args,
exc_info, func, extra, sinfo)
self.handle(record) def handle(self, record):
"""
Call the handlers for the specified record. This method is used for unpickled records received from a socket, as
well as those created locally. Logger-level filtering is applied.
"""
if (not self.disabled) and self.filter(record):
self.callHandlers(record) def addHandler(self, hdlr):
"""
Add the specified handler to this logger.
"""
_acquireLock()
try:
if not (hdlr in self.handlers):
self.handlers.append(hdlr)
finally:
_releaseLock() def removeHandler(self, hdlr):
"""
Remove the specified handler from this logger.
"""
_acquireLock()
try:
if hdlr in self.handlers:
self.handlers.remove(hdlr)
finally:
_releaseLock() def hasHandlers(self):
"""
See if this logger has any handlers configured. Loop through all handlers for this logger and its parents in the
logger hierarchy. Return True if a handler was found, else False.
Stop searching up the hierarchy whenever a logger with the "propagate"
attribute set to zero is found - that will be the last logger which
is checked for the existence of handlers.
"""
c = self
rv = False
while c:
if c.handlers:
rv = True
break
if not c.propagate:
break
else:
c = c.parent
return rv def callHandlers(self, record):
"""
Pass a record to all relevant handlers. Loop through all handlers for this logger and its parents in the
logger hierarchy. If no handler was found, output a one-off error
message to sys.stderr. Stop searching up the hierarchy whenever a
logger with the "propagate" attribute set to zero is found - that
will be the last logger whose handlers are called.
"""
c = self
found = 0
while c:
for hdlr in c.handlers:
found = found + 1
if record.levelno >= hdlr.level:
hdlr.handle(record)
if not c.propagate:
c = None #break out
else:
c = c.parent
if (found == 0):
if lastResort:
if record.levelno >= lastResort.level:
lastResort.handle(record)
elif raiseExceptions and not self.manager.emittedNoHandlerWarning:
sys.stderr.write("No handlers could be found for logger"
" \"%s\"\n" % self.name)
self.manager.emittedNoHandlerWarning = True def getEffectiveLevel(self):
"""
Get the effective level for this logger. Loop through this logger and its parents in the logger hierarchy,
looking for a non-zero logging level. Return the first one found.
"""
logger = self
while logger:
if logger.level:
return logger.level
logger = logger.parent
return NOTSET def isEnabledFor(self, level):
"""
Is this logger enabled for level 'level'?
"""
if self.manager.disable >= level:
return False
return level >= self.getEffectiveLevel() def getChild(self, suffix):
"""
Get a logger which is a descendant to this one. This is a convenience method, such that logging.getLogger('abc').getChild('def.ghi') is the same as logging.getLogger('abc.def.ghi') It's useful, for example, when the parent logger is named using
__name__ rather than a literal string.
"""
if self.root is not self:
suffix = '.'.join((self.name, suffix))
return self.manager.getLogger(suffix) def __repr__(self):
level = getLevelName(self.getEffectiveLevel())
return '<%s %s (%s)>' % (self.__class__.__name__, self.name, level) class RootLogger(Logger):
"""
A root logger is not that different to any other logger, except that
it must have a logging level and there is only one instance of it in
the hierarchy.
"""
def __init__(self, level):
"""
Initialize the logger with the name "root".
"""
Logger.__init__(self, "root", level) _loggerClass = Logger class LoggerAdapter(object):
"""
An adapter for loggers which makes it easier to specify contextual
information in logging output.
""" def __init__(self, logger, extra):
"""
Initialize the adapter with a logger and a dict-like object which
provides contextual information. This constructor signature allows
easy stacking of LoggerAdapters, if so desired. You can effectively pass keyword arguments as shown in the
following example: adapter = LoggerAdapter(someLogger, dict(p1=v1, p2="v2"))
"""
self.logger = logger
self.extra = extra def process(self, msg, kwargs):
"""
Process the logging message and keyword arguments passed in to
a logging call to insert contextual information. You can either
manipulate the message itself, the keyword args or both. Return
the message and kwargs modified (or not) to suit your needs. Normally, you'll only need to override this one method in a
LoggerAdapter subclass for your specific needs.
"""
kwargs["extra"] = self.extra
return msg, kwargs #
# Boilerplate convenience methods
#
def debug(self, msg, *args, **kwargs):
"""
Delegate a debug call to the underlying logger.
"""
self.log(DEBUG, msg, *args, **kwargs) def info(self, msg, *args, **kwargs):
"""
Delegate an info call to the underlying logger.
"""
self.log(INFO, msg, *args, **kwargs) def warning(self, msg, *args, **kwargs):
"""
Delegate a warning call to the underlying logger.
"""
self.log(WARNING, msg, *args, **kwargs) def warn(self, msg, *args, **kwargs):
warnings.warn("The 'warn' method is deprecated, "
"use 'warning' instead", DeprecationWarning, 2)
self.warning(msg, *args, **kwargs) def error(self, msg, *args, **kwargs):
"""
Delegate an error call to the underlying logger.
"""
self.log(ERROR, msg, *args, **kwargs) def exception(self, msg, *args, exc_info=True, **kwargs):
"""
Delegate an exception call to the underlying logger.
"""
self.log(ERROR, msg, *args, exc_info=exc_info, **kwargs) def critical(self, msg, *args, **kwargs):
"""
Delegate a critical call to the underlying logger.
"""
self.log(CRITICAL, msg, *args, **kwargs) def log(self, level, msg, *args, **kwargs):
"""
Delegate a log call to the underlying logger, after adding
contextual information from this adapter instance.
"""
if self.isEnabledFor(level):
msg, kwargs = self.process(msg, kwargs)
self.logger._log(level, msg, args, **kwargs) def isEnabledFor(self, level):
"""
Is this logger enabled for level 'level'?
"""
if self.logger.manager.disable >= level:
return False
return level >= self.getEffectiveLevel() def setLevel(self, level):
"""
Set the specified level on the underlying logger.
"""
self.logger.setLevel(level) def getEffectiveLevel(self):
"""
Get the effective level for the underlying logger.
"""
return self.logger.getEffectiveLevel() def hasHandlers(self):
"""
See if the underlying logger has any handlers.
"""
return self.logger.hasHandlers() def _log(self, level, msg, args, exc_info=None, extra=None, stack_info=False):
"""
Low-level log implementation, proxied to allow nested logger adapters.
"""
return self.logger._log(
level,
msg,
args,
exc_info=exc_info,
extra=extra,
stack_info=stack_info,
) @property
def manager(self):
return self.logger.manager @manager.setter
def set_manager(self, value):
self.logger.manager = value def __repr__(self):
logger = self.logger
level = getLevelName(logger.getEffectiveLevel())
return '<%s %s (%s)>' % (self.__class__.__name__, logger.name, level) root = RootLogger(WARNING)
Logger.root = root
Logger.manager = Manager(Logger.root) #---------------------------------------------------------------------------
# Configuration classes and functions
#--------------------------------------------------------------------------- def basicConfig(**kwargs):
"""
Do basic configuration for the logging system. This function does nothing if the root logger already has handlers
configured. It is a convenience method intended for use by simple scripts
to do one-shot configuration of the logging package. The default behaviour is to create a StreamHandler which writes to
sys.stderr, set a formatter using the BASIC_FORMAT format string, and
add the handler to the root logger. A number of optional keyword arguments may be specified, which can alter
the default behaviour. filename Specifies that a FileHandler be created, using the specified
filename, rather than a StreamHandler.
filemode Specifies the mode to open the file, if filename is specified
(if filemode is unspecified, it defaults to 'a').
format Use the specified format string for the handler.
datefmt Use the specified date/time format.
style If a format string is specified, use this to specify the
type of format string (possible values '%', '{', '$', for
%-formatting, :meth:`str.format` and :class:`string.Template`
- defaults to '%').
level Set the root logger level to the specified level.
stream Use the specified stream to initialize the StreamHandler. Note
that this argument is incompatible with 'filename' - if both
are present, 'stream' is ignored.
handlers If specified, this should be an iterable of already created
handlers, which will be added to the root handler. Any handler
in the list which does not have a formatter assigned will be
assigned the formatter created in this function. Note that you could specify a stream created using open(filename, mode)
rather than passing the filename and mode in. However, it should be
remembered that StreamHandler does not close its stream (since it may be
using sys.stdout or sys.stderr), whereas FileHandler closes its stream
when the handler is closed. .. versionchanged:: 3.2
Added the ``style`` parameter. .. versionchanged:: 3.3
Added the ``handlers`` parameter. A ``ValueError`` is now thrown for
incompatible arguments (e.g. ``handlers`` specified together with
``filename``/``filemode``, or ``filename``/``filemode`` specified
together with ``stream``, or ``handlers`` specified together with
``stream``.
"""
# Add thread safety in case someone mistakenly calls
# basicConfig() from multiple threads
_acquireLock()
try:
if len(root.handlers) == 0:
handlers = kwargs.pop("handlers", None)
if handlers is None:
if "stream" in kwargs and "filename" in kwargs:
raise ValueError("'stream' and 'filename' should not be "
"specified together")
else:
if "stream" in kwargs or "filename" in kwargs:
raise ValueError("'stream' or 'filename' should not be "
"specified together with 'handlers'")
if handlers is None:
filename = kwargs.pop("filename", None)
mode = kwargs.pop("filemode", 'a')
if filename:
h = FileHandler(filename, mode)
else:
stream = kwargs.pop("stream", None)
h = StreamHandler(stream)
handlers = [h]
dfs = kwargs.pop("datefmt", None)
style = kwargs.pop("style", '%')
if style not in _STYLES:
raise ValueError('Style must be one of: %s' % ','.join(
_STYLES.keys()))
fs = kwargs.pop("format", _STYLES[style][1])
fmt = Formatter(fs, dfs, style)
for h in handlers:
if h.formatter is None:
h.setFormatter(fmt)
root.addHandler(h)
level = kwargs.pop("level", None)
if level is not None:
root.setLevel(level)
if kwargs:
keys = ', '.join(kwargs.keys())
raise ValueError('Unrecognised argument(s): %s' % keys)
finally:
_releaseLock() #---------------------------------------------------------------------------
# Utility functions at module level.
# Basically delegate everything to the root logger.
#--------------------------------------------------------------------------- def getLogger(name=None):
"""
Return a logger with the specified name, creating it if necessary. If no name is specified, return the root logger.
"""
if name:
return Logger.manager.getLogger(name)
else:
return root def critical(msg, *args, **kwargs):
"""
Log a message with severity 'CRITICAL' on the root logger. If the logger
has no handlers, call basicConfig() to add a console handler with a
pre-defined format.
"""
if len(root.handlers) == 0:
basicConfig()
root.critical(msg, *args, **kwargs) fatal = critical def error(msg, *args, **kwargs):
"""
Log a message with severity 'ERROR' on the root logger. If the logger has
no handlers, call basicConfig() to add a console handler with a pre-defined
format.
"""
if len(root.handlers) == 0:
basicConfig()
root.error(msg, *args, **kwargs) def exception(msg, *args, exc_info=True, **kwargs):
"""
Log a message with severity 'ERROR' on the root logger, with exception
information. If the logger has no handlers, basicConfig() is called to add
a console handler with a pre-defined format.
"""
error(msg, *args, exc_info=exc_info, **kwargs) def warning(msg, *args, **kwargs):
"""
Log a message with severity 'WARNING' on the root logger. If the logger has
no handlers, call basicConfig() to add a console handler with a pre-defined
format.
"""
if len(root.handlers) == 0:
basicConfig()
root.warning(msg, *args, **kwargs) def warn(msg, *args, **kwargs):
warnings.warn("The 'warn' function is deprecated, "
"use 'warning' instead", DeprecationWarning, 2)
warning(msg, *args, **kwargs) def info(msg, *args, **kwargs):
"""
Log a message with severity 'INFO' on the root logger. If the logger has
no handlers, call basicConfig() to add a console handler with a pre-defined
format.
"""
if len(root.handlers) == 0:
basicConfig()
root.info(msg, *args, **kwargs) def debug(msg, *args, **kwargs):
"""
Log a message with severity 'DEBUG' on the root logger. If the logger has
no handlers, call basicConfig() to add a console handler with a pre-defined
format.
"""
if len(root.handlers) == 0:
basicConfig()
root.debug(msg, *args, **kwargs) def log(level, msg, *args, **kwargs):
"""
Log 'msg % args' with the integer severity 'level' on the root logger. If
the logger has no handlers, call basicConfig() to add a console handler
with a pre-defined format.
"""
if len(root.handlers) == 0:
basicConfig()
root.log(level, msg, *args, **kwargs) def disable(level):
"""
Disable all logging calls of severity 'level' and below.
"""
root.manager.disable = level def shutdown(handlerList=_handlerList):
"""
Perform any cleanup actions in the logging system (e.g. flushing
buffers). Should be called at application exit.
"""
for wr in reversed(handlerList[:]):
#errors might occur, for example, if files are locked
#we just ignore them if raiseExceptions is not set
try:
h = wr()
if h:
try:
h.acquire()
h.flush()
h.close()
except (OSError, ValueError):
# Ignore errors which might be caused
# because handlers have been closed but
# references to them are still around at
# application exit.
pass
finally:
h.release()
except: # ignore everything, as we're shutting down
if raiseExceptions:
raise
#else, swallow #Let's try and shutdown automatically on application exit...
import atexit
atexit.register(shutdown) # Null handler class NullHandler(Handler):
"""
This handler does nothing. It's intended to be used to avoid the
"No handlers could be found for logger XXX" one-off warning. This is
important for library code, which may contain code to log events. If a user
of the library does not configure logging, the one-off warning might be
produced; to avoid this, the library developer simply needs to instantiate
a NullHandler and add it to the top-level logger of the library module or
package.
"""
def handle(self, record):
"""Stub.""" def emit(self, record):
"""Stub.""" def createLock(self):
self.lock = None # Warnings integration _warnings_showwarning = None def _showwarning(message, category, filename, lineno, file=None, line=None):
"""
Implementation of showwarnings which redirects to logging, which will first
check to see if the file parameter is None. If a file is specified, it will
delegate to the original warnings implementation of showwarning. Otherwise,
it will call warnings.formatwarning and will log the resulting string to a
warnings logger named "py.warnings" with level logging.WARNING.
"""
if file is not None:
if _warnings_showwarning is not None:
_warnings_showwarning(message, category, filename, lineno, file, line)
else:
s = warnings.formatwarning(message, category, filename, lineno, line)
logger = getLogger("py.warnings")
if not logger.handlers:
logger.addHandler(NullHandler())
logger.warning("%s", s) def captureWarnings(capture):
"""
If capture is true, redirect all warnings to the logging package.
If capture is False, ensure that warnings are not redirected to logging
but to their original destinations.
"""
global _warnings_showwarning
if capture:
if _warnings_showwarning is None:
_warnings_showwarning = warnings.showwarning
warnings.showwarning = _showwarning
else:
if _warnings_showwarning is not None:
warnings.showwarning = _warnings_showwarning
_warnings_showwarning = None
python:logging
# Copyright 2001-2016 by Vinay Sajip. All Rights Reserved.
#
# Permission to use, copy, modify, and distribute this software and its
# documentation for any purpose and without fee is hereby granted,
# provided that the above copyright notice appear in all copies and that
# both that copyright notice and this permission notice appear in
# supporting documentation, and that the name of Vinay Sajip
# not be used in advertising or publicity pertaining to distribution
# of the software without specific, written prior permission.
# VINAY SAJIP DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
# ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
# VINAY SAJIP BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
# ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
# IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. """
Logging package for Python. Based on PEP 282 and comments thereto in
comp.lang.python. Copyright (C) 2001-2016 Vinay Sajip. All Rights Reserved. To use, simply 'import logging' and log away!
""" import sys, os, time, io, traceback, warnings, weakref, collections from string import Template __all__ = ['BASIC_FORMAT', 'BufferingFormatter', 'CRITICAL', 'DEBUG', 'ERROR',
'FATAL', 'FileHandler', 'Filter', 'Formatter', 'Handler', 'INFO',
'LogRecord', 'Logger', 'LoggerAdapter', 'NOTSET', 'NullHandler',
'StreamHandler', 'WARN', 'WARNING', 'addLevelName', 'basicConfig',
'captureWarnings', 'critical', 'debug', 'disable', 'error',
'exception', 'fatal', 'getLevelName', 'getLogger', 'getLoggerClass',
'info', 'log', 'makeLogRecord', 'setLoggerClass', 'shutdown',
'warn', 'warning', 'getLogRecordFactory', 'setLogRecordFactory',
'lastResort', 'raiseExceptions'] try:
import threading
except ImportError: #pragma: no cover
threading = None __author__ = "Vinay Sajip <vinay_sajip@red-dove.com>"
__status__ = "production"
# The following module attributes are no longer updated.
__version__ = "0.5.1.2"
__date__ = "07 February 2010" #---------------------------------------------------------------------------
# Miscellaneous module data
#--------------------------------------------------------------------------- #
#_startTime is used as the base when calculating the relative time of events
#
_startTime = time.time() #
#raiseExceptions is used to see if exceptions during handling should be
#propagated
#
raiseExceptions = True #
# If you don't want threading information in the log, set this to zero
#
logThreads = True #
# If you don't want multiprocessing information in the log, set this to zero
#
logMultiprocessing = True #
# If you don't want process information in the log, set this to zero
#
logProcesses = True #---------------------------------------------------------------------------
# Level related stuff
#---------------------------------------------------------------------------
#
# Default levels and level names, these can be replaced with any positive set
# of values having corresponding names. There is a pseudo-level, NOTSET, which
# is only really there as a lower limit for user-defined levels. Handlers and
# loggers are initialized with NOTSET so that they will log all messages, even
# at user-defined levels.
# CRITICAL = 50
FATAL = CRITICAL
ERROR = 40
WARNING = 30
WARN = WARNING
INFO = 20
DEBUG = 10
NOTSET = 0 _levelToName = {
CRITICAL: 'CRITICAL',
ERROR: 'ERROR',
WARNING: 'WARNING',
INFO: 'INFO',
DEBUG: 'DEBUG',
NOTSET: 'NOTSET',
}
_nameToLevel = {
'CRITICAL': CRITICAL,
'FATAL': FATAL,
'ERROR': ERROR,
'WARN': WARNING,
'WARNING': WARNING,
'INFO': INFO,
'DEBUG': DEBUG,
'NOTSET': NOTSET,
} def getLevelName(level):
"""
Return the textual representation of logging level 'level'. If the level is one of the predefined levels (CRITICAL, ERROR, WARNING,
INFO, DEBUG) then you get the corresponding string. If you have
associated levels with names using addLevelName then the name you have
associated with 'level' is returned. If a numeric value corresponding to one of the defined levels is passed
in, the corresponding string representation is returned. Otherwise, the string "Level %s" % level is returned.
"""
# See Issues #22386, #27937 and #29220 for why it's this way
result = _levelToName.get(level)
if result is not None:
return result
result = _nameToLevel.get(level)
if result is not None:
return result
return "Level %s" % level def addLevelName(level, levelName):
"""
Associate 'levelName' with 'level'. This is used when converting levels to text during message formatting.
"""
_acquireLock()
try: #unlikely to cause an exception, but you never know...
_levelToName[level] = levelName
_nameToLevel[levelName] = level
finally:
_releaseLock() if hasattr(sys, '_getframe'):
currentframe = lambda: sys._getframe(3)
else: #pragma: no cover
def currentframe():
"""Return the frame object for the caller's stack frame."""
try:
raise Exception
except Exception:
return sys.exc_info()[2].tb_frame.f_back #
# _srcfile is used when walking the stack to check when we've got the first
# caller stack frame, by skipping frames whose filename is that of this
# module's source. It therefore should contain the filename of this module's
# source file.
#
# Ordinarily we would use __file__ for this, but frozen modules don't always
# have __file__ set, for some reason (see Issue #21736). Thus, we get the
# filename from a handy code object from a function defined in this module.
# (There's no particular reason for picking addLevelName.)
# _srcfile = os.path.normcase(addLevelName.__code__.co_filename) # _srcfile is only used in conjunction with sys._getframe().
# To provide compatibility with older versions of Python, set _srcfile
# to None if _getframe() is not available; this value will prevent
# findCaller() from being called. You can also do this if you want to avoid
# the overhead of fetching caller information, even when _getframe() is
# available.
#if not hasattr(sys, '_getframe'):
# _srcfile = None def _checkLevel(level):
if isinstance(level, int):
rv = level
elif str(level) == level:
if level not in _nameToLevel:
raise ValueError("Unknown level: %r" % level)
rv = _nameToLevel[level]
else:
raise TypeError("Level not an integer or a valid string: %r" % level)
return rv #---------------------------------------------------------------------------
# Thread-related stuff
#--------------------------------------------------------------------------- #
#_lock is used to serialize access to shared data structures in this module.
#This needs to be an RLock because fileConfig() creates and configures
#Handlers, and so might arbitrary user threads. Since Handler code updates the
#shared dictionary _handlers, it needs to acquire the lock. But if configuring,
#the lock would already have been acquired - so we need an RLock.
#The same argument applies to Loggers and Manager.loggerDict.
#
if threading:
_lock = threading.RLock()
else: #pragma: no cover
_lock = None def _acquireLock():
"""
Acquire the module-level lock for serializing access to shared data. This should be released with _releaseLock().
"""
if _lock:
_lock.acquire() def _releaseLock():
"""
Release the module-level lock acquired by calling _acquireLock().
"""
if _lock:
_lock.release() #---------------------------------------------------------------------------
# The logging record
#--------------------------------------------------------------------------- class LogRecord(object):
"""
A LogRecord instance represents an event being logged. LogRecord instances are created every time something is logged. They
contain all the information pertinent to the event being logged. The
main information passed in is in msg and args, which are combined
using str(msg) % args to create the message field of the record. The
record also includes information such as when the record was created,
the source line where the logging call was made, and any exception
information to be logged.
"""
def __init__(self, name, level, pathname, lineno,
msg, args, exc_info, func=None, sinfo=None, **kwargs):
"""
Initialize a logging record with interesting information.
"""
ct = time.time()
self.name = name
self.msg = msg
#
# The following statement allows passing of a dictionary as a sole
# argument, so that you can do something like
# logging.debug("a %(a)d b %(b)s", {'a':1, 'b':2})
# Suggested by Stefan Behnel.
# Note that without the test for args[0], we get a problem because
# during formatting, we test to see if the arg is present using
# 'if self.args:'. If the event being logged is e.g. 'Value is %d'
# and if the passed arg fails 'if self.args:' then no formatting
# is done. For example, logger.warning('Value is %d', 0) would log
# 'Value is %d' instead of 'Value is 0'.
# For the use case of passing a dictionary, this should not be a
# problem.
# Issue #21172: a request was made to relax the isinstance check
# to hasattr(args[0], '__getitem__'). However, the docs on string
# formatting still seem to suggest a mapping object is required.
# Thus, while not removing the isinstance check, it does now look
# for collections.Mapping rather than, as before, dict.
if (args and len(args) == 1 and isinstance(args[0], collections.Mapping)
and args[0]):
args = args[0]
self.args = args
self.levelname = getLevelName(level)
self.levelno = level
self.pathname = pathname
try:
self.filename = os.path.basename(pathname)
self.module = os.path.splitext(self.filename)[0]
except (TypeError, ValueError, AttributeError):
self.filename = pathname
self.module = "Unknown module"
self.exc_info = exc_info
self.exc_text = None # used to cache the traceback text
self.stack_info = sinfo
self.lineno = lineno
self.funcName = func
self.created = ct
self.msecs = (ct - int(ct)) * 1000
self.relativeCreated = (self.created - _startTime) * 1000
if logThreads and threading:
self.thread = threading.get_ident()
self.threadName = threading.current_thread().name
else: # pragma: no cover
self.thread = None
self.threadName = None
if not logMultiprocessing: # pragma: no cover
self.processName = None
else:
self.processName = 'MainProcess'
mp = sys.modules.get('multiprocessing')
if mp is not None:
# Errors may occur if multiprocessing has not finished loading
# yet - e.g. if a custom import hook causes third-party code
# to run when multiprocessing calls import. See issue 8200
# for an example
try:
self.processName = mp.current_process().name
except Exception: #pragma: no cover
pass
if logProcesses and hasattr(os, 'getpid'):
self.process = os.getpid()
else:
self.process = None def __str__(self):
return '<LogRecord: %s, %s, %s, %s, "%s">'%(self.name, self.levelno,
self.pathname, self.lineno, self.msg) __repr__ = __str__ def getMessage(self):
"""
Return the message for this LogRecord. Return the message for this LogRecord after merging any user-supplied
arguments with the message.
"""
msg = str(self.msg)
if self.args:
msg = msg % self.args
return msg #
# Determine which class to use when instantiating log records.
#
_logRecordFactory = LogRecord def setLogRecordFactory(factory):
"""
Set the factory to be used when instantiating a log record. :param factory: A callable which will be called to instantiate
a log record.
"""
global _logRecordFactory
_logRecordFactory = factory def getLogRecordFactory():
"""
Return the factory to be used when instantiating a log record.
""" return _logRecordFactory def makeLogRecord(dict):
"""
Make a LogRecord whose attributes are defined by the specified dictionary,
This function is useful for converting a logging event received over
a socket connection (which is sent as a dictionary) into a LogRecord
instance.
"""
rv = _logRecordFactory(None, None, "", 0, "", (), None, None)
rv.__dict__.update(dict)
return rv #---------------------------------------------------------------------------
# Formatter classes and functions
#--------------------------------------------------------------------------- class PercentStyle(object): default_format = '%(message)s'
asctime_format = '%(asctime)s'
asctime_search = '%(asctime)' def __init__(self, fmt):
self._fmt = fmt or self.default_format def usesTime(self):
return self._fmt.find(self.asctime_search) >= 0 def format(self, record):
return self._fmt % record.__dict__ class StrFormatStyle(PercentStyle):
default_format = '{message}'
asctime_format = '{asctime}'
asctime_search = '{asctime' def format(self, record):
return self._fmt.format(**record.__dict__) class StringTemplateStyle(PercentStyle):
default_format = '${message}'
asctime_format = '${asctime}'
asctime_search = '${asctime}' def __init__(self, fmt):
self._fmt = fmt or self.default_format
self._tpl = Template(self._fmt) def usesTime(self):
fmt = self._fmt
return fmt.find('$asctime') >= 0 or fmt.find(self.asctime_format) >= 0 def format(self, record):
return self._tpl.substitute(**record.__dict__) BASIC_FORMAT = "%(levelname)s:%(name)s:%(message)s" _STYLES = {
'%': (PercentStyle, BASIC_FORMAT),
'{': (StrFormatStyle, '{levelname}:{name}:{message}'),
'$': (StringTemplateStyle, '${levelname}:${name}:${message}'),
} class Formatter(object):
"""
Formatter instances are used to convert a LogRecord to text. Formatters need to know how a LogRecord is constructed. They are
responsible for converting a LogRecord to (usually) a string which can
be interpreted by either a human or an external system. The base Formatter
allows a formatting string to be specified. If none is supplied, the
default value of "%s(message)" is used. The Formatter can be initialized with a format string which makes use of
knowledge of the LogRecord attributes - e.g. the default value mentioned
above makes use of the fact that the user's message and arguments are pre-
formatted into a LogRecord's message attribute. Currently, the useful
attributes in a LogRecord are described by: %(name)s Name of the logger (logging channel)
%(levelno)s Numeric logging level for the message (DEBUG, INFO,
WARNING, ERROR, CRITICAL)
%(levelname)s Text logging level for the message ("DEBUG", "INFO",
"WARNING", "ERROR", "CRITICAL")
%(pathname)s Full pathname of the source file where the logging
call was issued (if available)
%(filename)s Filename portion of pathname
%(module)s Module (name portion of filename)
%(lineno)d Source line number where the logging call was issued
(if available)
%(funcName)s Function name
%(created)f Time when the LogRecord was created (time.time()
return value)
%(asctime)s Textual time when the LogRecord was created
%(msecs)d Millisecond portion of the creation time
%(relativeCreated)d Time in milliseconds when the LogRecord was created,
relative to the time the logging module was loaded
(typically at application startup time)
%(thread)d Thread ID (if available)
%(threadName)s Thread name (if available)
%(process)d Process ID (if available)
%(message)s The result of record.getMessage(), computed just as
the record is emitted
""" converter = time.localtime def __init__(self, fmt=None, datefmt=None, style='%'):
"""
Initialize the formatter with specified format strings. Initialize the formatter either with the specified format string, or a
default as described above. Allow for specialized date formatting with
the optional datefmt argument (if omitted, you get the ISO8601 format). Use a style parameter of '%', '{' or '$' to specify that you want to
use one of %-formatting, :meth:`str.format` (``{}``) formatting or
:class:`string.Template` formatting in your format string. .. versionchanged:: 3.2
Added the ``style`` parameter.
"""
if style not in _STYLES:
raise ValueError('Style must be one of: %s' % ','.join(
_STYLES.keys()))
self._style = _STYLES[style][0](fmt)
self._fmt = self._style._fmt
self.datefmt = datefmt default_time_format = '%Y-%m-%d %H:%M:%S'
default_msec_format = '%s,%03d' def formatTime(self, record, datefmt=None):
"""
Return the creation time of the specified LogRecord as formatted text. This method should be called from format() by a formatter which
wants to make use of a formatted time. This method can be overridden
in formatters to provide for any specific requirement, but the
basic behaviour is as follows: if datefmt (a string) is specified,
it is used with time.strftime() to format the creation time of the
record. Otherwise, the ISO8601 format is used. The resulting
string is returned. This function uses a user-configurable function
to convert the creation time to a tuple. By default, time.localtime()
is used; to change this for a particular formatter instance, set the
'converter' attribute to a function with the same signature as
time.localtime() or time.gmtime(). To change it for all formatters,
for example if you want all logging times to be shown in GMT,
set the 'converter' attribute in the Formatter class.
"""
ct = self.converter(record.created)
if datefmt:
s = time.strftime(datefmt, ct)
else:
t = time.strftime(self.default_time_format, ct)
s = self.default_msec_format % (t, record.msecs)
return s def formatException(self, ei):
"""
Format and return the specified exception information as a string. This default implementation just uses
traceback.print_exception()
"""
sio = io.StringIO()
tb = ei[2]
# See issues #9427, #1553375. Commented out for now.
#if getattr(self, 'fullstack', False):
# traceback.print_stack(tb.tb_frame.f_back, file=sio)
traceback.print_exception(ei[0], ei[1], tb, None, sio)
s = sio.getvalue()
sio.close()
if s[-1:] == "\n":
s = s[:-1]
return s def usesTime(self):
"""
Check if the format uses the creation time of the record.
"""
return self._style.usesTime() def formatMessage(self, record):
return self._style.format(record) def formatStack(self, stack_info):
"""
This method is provided as an extension point for specialized
formatting of stack information. The input data is a string as returned from a call to
:func:`traceback.print_stack`, but with the last trailing newline
removed. The base implementation just returns the value passed in.
"""
return stack_info def format(self, record):
"""
Format the specified record as text. The record's attribute dictionary is used as the operand to a
string formatting operation which yields the returned string.
Before formatting the dictionary, a couple of preparatory steps
are carried out. The message attribute of the record is computed
using LogRecord.getMessage(). If the formatting string uses the
time (as determined by a call to usesTime(), formatTime() is
called to format the event time. If there is exception information,
it is formatted using formatException() and appended to the message.
"""
record.message = record.getMessage()
if self.usesTime():
record.asctime = self.formatTime(record, self.datefmt)
s = self.formatMessage(record)
if record.exc_info:
# Cache the traceback text to avoid converting it multiple times
# (it's constant anyway)
if not record.exc_text:
record.exc_text = self.formatException(record.exc_info)
if record.exc_text:
if s[-1:] != "\n":
s = s + "\n"
s = s + record.exc_text
if record.stack_info:
if s[-1:] != "\n":
s = s + "\n"
s = s + self.formatStack(record.stack_info)
return s #
# The default formatter to use when no other is specified
#
_defaultFormatter = Formatter() class BufferingFormatter(object):
"""
A formatter suitable for formatting a number of records.
"""
def __init__(self, linefmt=None):
"""
Optionally specify a formatter which will be used to format each
individual record.
"""
if linefmt:
self.linefmt = linefmt
else:
self.linefmt = _defaultFormatter def formatHeader(self, records):
"""
Return the header string for the specified records.
"""
return "" def formatFooter(self, records):
"""
Return the footer string for the specified records.
"""
return "" def format(self, records):
"""
Format the specified records and return the result as a string.
"""
rv = ""
if len(records) > 0:
rv = rv + self.formatHeader(records)
for record in records:
rv = rv + self.linefmt.format(record)
rv = rv + self.formatFooter(records)
return rv #---------------------------------------------------------------------------
# Filter classes and functions
#--------------------------------------------------------------------------- class Filter(object):
"""
Filter instances are used to perform arbitrary filtering of LogRecords. Loggers and Handlers can optionally use Filter instances to filter
records as desired. The base filter class only allows events which are
below a certain point in the logger hierarchy. For example, a filter
initialized with "A.B" will allow events logged by loggers "A.B",
"A.B.C", "A.B.C.D", "A.B.D" etc. but not "A.BB", "B.A.B" etc. If
initialized with the empty string, all events are passed.
"""
def __init__(self, name=''):
"""
Initialize a filter. Initialize with the name of the logger which, together with its
children, will have its events allowed through the filter. If no
name is specified, allow every event.
"""
self.name = name
self.nlen = len(name) def filter(self, record):
"""
Determine if the specified record is to be logged. Is the specified record to be logged? Returns 0 for no, nonzero for
yes. If deemed appropriate, the record may be modified in-place.
"""
if self.nlen == 0:
return True
elif self.name == record.name:
return True
elif record.name.find(self.name, 0, self.nlen) != 0:
return False
return (record.name[self.nlen] == ".") class Filterer(object):
"""
A base class for loggers and handlers which allows them to share
common code.
"""
def __init__(self):
"""
Initialize the list of filters to be an empty list.
"""
self.filters = [] def addFilter(self, filter):
"""
Add the specified filter to this handler.
"""
if not (filter in self.filters):
self.filters.append(filter) def removeFilter(self, filter):
"""
Remove the specified filter from this handler.
"""
if filter in self.filters:
self.filters.remove(filter) def filter(self, record):
"""
Determine if a record is loggable by consulting all the filters. The default is to allow the record to be logged; any filter can veto
this and the record is then dropped. Returns a zero value if a record
is to be dropped, else non-zero. .. versionchanged:: 3.2 Allow filters to be just callables.
"""
rv = True
for f in self.filters:
if hasattr(f, 'filter'):
result = f.filter(record)
else:
result = f(record) # assume callable - will raise if not
if not result:
rv = False
break
return rv #---------------------------------------------------------------------------
# Handler classes and functions
#--------------------------------------------------------------------------- _handlers = weakref.WeakValueDictionary() #map of handler names to handlers
_handlerList = [] # added to allow handlers to be removed in reverse of order initialized def _removeHandlerRef(wr):
"""
Remove a handler reference from the internal cleanup list.
"""
# This function can be called during module teardown, when globals are
# set to None. It can also be called from another thread. So we need to
# pre-emptively grab the necessary globals and check if they're None,
# to prevent race conditions and failures during interpreter shutdown.
acquire, release, handlers = _acquireLock, _releaseLock, _handlerList
if acquire and release and handlers:
acquire()
try:
if wr in handlers:
handlers.remove(wr)
finally:
release() def _addHandlerRef(handler):
"""
Add a handler to the internal cleanup list using a weak reference.
"""
_acquireLock()
try:
_handlerList.append(weakref.ref(handler, _removeHandlerRef))
finally:
_releaseLock() class Handler(Filterer):
"""
Handler instances dispatch logging events to specific destinations. The base handler class. Acts as a placeholder which defines the Handler
interface. Handlers can optionally use Formatter instances to format
records as desired. By default, no formatter is specified; in this case,
the 'raw' message as determined by record.message is logged.
"""
def __init__(self, level=NOTSET):
"""
Initializes the instance - basically setting the formatter to None
and the filter list to empty.
"""
Filterer.__init__(self)
self._name = None
self.level = _checkLevel(level)
self.formatter = None
# Add the handler to the global _handlerList (for cleanup on shutdown)
_addHandlerRef(self)
self.createLock() def get_name(self):
return self._name def set_name(self, name):
_acquireLock()
try:
if self._name in _handlers:
del _handlers[self._name]
self._name = name
if name:
_handlers[name] = self
finally:
_releaseLock() name = property(get_name, set_name) def createLock(self):
"""
Acquire a thread lock for serializing access to the underlying I/O.
"""
if threading:
self.lock = threading.RLock()
else: #pragma: no cover
self.lock = None def acquire(self):
"""
Acquire the I/O thread lock.
"""
if self.lock:
self.lock.acquire() def release(self):
"""
Release the I/O thread lock.
"""
if self.lock:
self.lock.release() def setLevel(self, level):
"""
Set the logging level of this handler. level must be an int or a str.
"""
self.level = _checkLevel(level) def format(self, record):
"""
Format the specified record. If a formatter is set, use it. Otherwise, use the default formatter
for the module.
"""
if self.formatter:
fmt = self.formatter
else:
fmt = _defaultFormatter
return fmt.format(record) def emit(self, record):
"""
Do whatever it takes to actually log the specified logging record. This version is intended to be implemented by subclasses and so
raises a NotImplementedError.
"""
raise NotImplementedError('emit must be implemented '
'by Handler subclasses') def handle(self, record):
"""
Conditionally emit the specified logging record. Emission depends on filters which may have been added to the handler.
Wrap the actual emission of the record with acquisition/release of
the I/O thread lock. Returns whether the filter passed the record for
emission.
"""
rv = self.filter(record)
if rv:
self.acquire()
try:
self.emit(record)
finally:
self.release()
return rv def setFormatter(self, fmt):
"""
Set the formatter for this handler.
"""
self.formatter = fmt def flush(self):
"""
Ensure all logging output has been flushed. This version does nothing and is intended to be implemented by
subclasses.
"""
pass def close(self):
"""
Tidy up any resources used by the handler. This version removes the handler from an internal map of handlers,
_handlers, which is used for handler lookup by name. Subclasses
should ensure that this gets called from overridden close()
methods.
"""
#get the module data lock, as we're updating a shared structure.
_acquireLock()
try: #unlikely to raise an exception, but you never know...
if self._name and self._name in _handlers:
del _handlers[self._name]
finally:
_releaseLock() def handleError(self, record):
"""
Handle errors which occur during an emit() call. This method should be called from handlers when an exception is
encountered during an emit() call. If raiseExceptions is false,
exceptions get silently ignored. This is what is mostly wanted
for a logging system - most users will not care about errors in
the logging system, they are more interested in application errors.
You could, however, replace this with a custom handler if you wish.
The record which was being processed is passed in to this method.
"""
if raiseExceptions and sys.stderr: # see issue 13807
t, v, tb = sys.exc_info()
try:
sys.stderr.write('--- Logging error ---\n')
traceback.print_exception(t, v, tb, None, sys.stderr)
sys.stderr.write('Call stack:\n')
# Walk the stack frame up until we're out of logging,
# so as to print the calling context.
frame = tb.tb_frame
while (frame and os.path.dirname(frame.f_code.co_filename) ==
__path__[0]):
frame = frame.f_back
if frame:
traceback.print_stack(frame, file=sys.stderr)
else:
# couldn't find the right stack frame, for some reason
sys.stderr.write('Logged from file %s, line %s\n' % (
record.filename, record.lineno))
# Issue 18671: output logging message and arguments
try:
sys.stderr.write('Message: %r\n'
'Arguments: %s\n' % (record.msg,
record.args))
except Exception:
sys.stderr.write('Unable to print the message and arguments'
' - possible formatting error.\nUse the'
' traceback above to help find the error.\n'
)
except OSError: #pragma: no cover
pass # see issue 5971
finally:
del t, v, tb def __repr__(self):
level = getLevelName(self.level)
return '<%s (%s)>' % (self.__class__.__name__, level) class StreamHandler(Handler):
"""
A handler class which writes logging records, appropriately formatted,
to a stream. Note that this class does not close the stream, as
sys.stdout or sys.stderr may be used.
""" terminator = '\n' def __init__(self, stream=None):
"""
Initialize the handler. If stream is not specified, sys.stderr is used.
"""
Handler.__init__(self)
if stream is None:
stream = sys.stderr
self.stream = stream def flush(self):
"""
Flushes the stream.
"""
self.acquire()
try:
if self.stream and hasattr(self.stream, "flush"):
self.stream.flush()
finally:
self.release() def emit(self, record):
"""
Emit a record. If a formatter is specified, it is used to format the record.
The record is then written to the stream with a trailing newline. If
exception information is present, it is formatted using
traceback.print_exception and appended to the stream. If the stream
has an 'encoding' attribute, it is used to determine how to do the
output to the stream.
"""
try:
msg = self.format(record)
stream = self.stream
stream.write(msg)
stream.write(self.terminator)
self.flush()
except Exception:
self.handleError(record) def __repr__(self):
level = getLevelName(self.level)
name = getattr(self.stream, 'name', '')
if name:
name += ' '
return '<%s %s(%s)>' % (self.__class__.__name__, name, level) class FileHandler(StreamHandler):
"""
A handler class which writes formatted logging records to disk files.
"""
def __init__(self, filename, mode='a', encoding=None, delay=False):
"""
Open the specified file and use it as the stream for logging.
"""
# Issue #27493: add support for Path objects to be passed in
filename = os.fspath(filename)
#keep the absolute path, otherwise derived classes which use this
#may come a cropper when the current directory changes
self.baseFilename = os.path.abspath(filename)
self.mode = mode
self.encoding = encoding
self.delay = delay
if delay:
#We don't open the stream, but we still need to call the
#Handler constructor to set level, formatter, lock etc.
Handler.__init__(self)
self.stream = None
else:
StreamHandler.__init__(self, self._open()) def close(self):
"""
Closes the stream.
"""
self.acquire()
try:
try:
if self.stream:
try:
self.flush()
finally:
stream = self.stream
self.stream = None
if hasattr(stream, "close"):
stream.close()
finally:
# Issue #19523: call unconditionally to
# prevent a handler leak when delay is set
StreamHandler.close(self)
finally:
self.release() def _open(self):
"""
Open the current base file with the (original) mode and encoding.
Return the resulting stream.
"""
return open(self.baseFilename, self.mode, encoding=self.encoding) def emit(self, record):
"""
Emit a record. If the stream was not opened because 'delay' was specified in the
constructor, open it before calling the superclass's emit.
"""
if self.stream is None:
self.stream = self._open()
StreamHandler.emit(self, record) def __repr__(self):
level = getLevelName(self.level)
return '<%s %s (%s)>' % (self.__class__.__name__, self.baseFilename, level) class _StderrHandler(StreamHandler):
"""
This class is like a StreamHandler using sys.stderr, but always uses
whatever sys.stderr is currently set to rather than the value of
sys.stderr at handler construction time.
"""
def __init__(self, level=NOTSET):
"""
Initialize the handler.
"""
Handler.__init__(self, level) @property
def stream(self):
return sys.stderr _defaultLastResort = _StderrHandler(WARNING)
lastResort = _defaultLastResort #---------------------------------------------------------------------------
# Manager classes and functions
#--------------------------------------------------------------------------- class PlaceHolder(object):
"""
PlaceHolder instances are used in the Manager logger hierarchy to take
the place of nodes for which no loggers have been defined. This class is
intended for internal use only and not as part of the public API.
"""
def __init__(self, alogger):
"""
Initialize with the specified logger being a child of this placeholder.
"""
self.loggerMap = { alogger : None } def append(self, alogger):
"""
Add the specified logger as a child of this placeholder.
"""
if alogger not in self.loggerMap:
self.loggerMap[alogger] = None #
# Determine which class to use when instantiating loggers.
# def setLoggerClass(klass):
"""
Set the class to be used when instantiating a logger. The class should
define __init__() such that only a name argument is required, and the
__init__() should call Logger.__init__()
"""
if klass != Logger:
if not issubclass(klass, Logger):
raise TypeError("logger not derived from logging.Logger: "
+ klass.__name__)
global _loggerClass
_loggerClass = klass def getLoggerClass():
"""
Return the class to be used when instantiating a logger.
"""
return _loggerClass class Manager(object):
"""
There is [under normal circumstances] just one Manager instance, which
holds the hierarchy of loggers.
"""
def __init__(self, rootnode):
"""
Initialize the manager with the root node of the logger hierarchy.
"""
self.root = rootnode
self.disable = 0
self.emittedNoHandlerWarning = False
self.loggerDict = {}
self.loggerClass = None
self.logRecordFactory = None def getLogger(self, name):
"""
Get a logger with the specified name (channel name), creating it
if it doesn't yet exist. This name is a dot-separated hierarchical
name, such as "a", "a.b", "a.b.c" or similar. If a PlaceHolder existed for the specified name [i.e. the logger
didn't exist but a child of it did], replace it with the created
logger and fix up the parent/child references which pointed to the
placeholder to now point to the logger.
"""
rv = None
if not isinstance(name, str):
raise TypeError('A logger name must be a string')
_acquireLock()
try:
if name in self.loggerDict:
rv = self.loggerDict[name]
if isinstance(rv, PlaceHolder):
ph = rv
rv = (self.loggerClass or _loggerClass)(name)
rv.manager = self
self.loggerDict[name] = rv
self._fixupChildren(ph, rv)
self._fixupParents(rv)
else:
rv = (self.loggerClass or _loggerClass)(name)
rv.manager = self
self.loggerDict[name] = rv
self._fixupParents(rv)
finally:
_releaseLock()
return rv def setLoggerClass(self, klass):
"""
Set the class to be used when instantiating a logger with this Manager.
"""
if klass != Logger:
if not issubclass(klass, Logger):
raise TypeError("logger not derived from logging.Logger: "
+ klass.__name__)
self.loggerClass = klass def setLogRecordFactory(self, factory):
"""
Set the factory to be used when instantiating a log record with this
Manager.
"""
self.logRecordFactory = factory def _fixupParents(self, alogger):
"""
Ensure that there are either loggers or placeholders all the way
from the specified logger to the root of the logger hierarchy.
"""
name = alogger.name
i = name.rfind(".")
rv = None
while (i > 0) and not rv:
substr = name[:i]
if substr not in self.loggerDict:
self.loggerDict[substr] = PlaceHolder(alogger)
else:
obj = self.loggerDict[substr]
if isinstance(obj, Logger):
rv = obj
else:
assert isinstance(obj, PlaceHolder)
obj.append(alogger)
i = name.rfind(".", 0, i - 1)
if not rv:
rv = self.root
alogger.parent = rv def _fixupChildren(self, ph, alogger):
"""
Ensure that children of the placeholder ph are connected to the
specified logger.
"""
name = alogger.name
namelen = len(name)
for c in ph.loggerMap.keys():
#The if means ... if not c.parent.name.startswith(nm)
if c.parent.name[:namelen] != name:
alogger.parent = c.parent
c.parent = alogger #---------------------------------------------------------------------------
# Logger classes and functions
#--------------------------------------------------------------------------- class Logger(Filterer):
"""
Instances of the Logger class represent a single logging channel. A
"logging channel" indicates an area of an application. Exactly how an
"area" is defined is up to the application developer. Since an
application can have any number of areas, logging channels are identified
by a unique string. Application areas can be nested (e.g. an area
of "input processing" might include sub-areas "read CSV files", "read
XLS files" and "read Gnumeric files"). To cater for this natural nesting,
channel names are organized into a namespace hierarchy where levels are
separated by periods, much like the Java or Python package namespace. So
in the instance given above, channel names might be "input" for the upper
level, and "input.csv", "input.xls" and "input.gnu" for the sub-levels.
There is no arbitrary limit to the depth of nesting.
"""
def __init__(self, name, level=NOTSET):
"""
Initialize the logger with a name and an optional level.
"""
Filterer.__init__(self)
self.name = name
self.level = _checkLevel(level)
self.parent = None
self.propagate = True
self.handlers = []
self.disabled = False def setLevel(self, level):
"""
Set the logging level of this logger. level must be an int or a str.
"""
self.level = _checkLevel(level) def debug(self, msg, *args, **kwargs):
"""
Log 'msg % args' with severity 'DEBUG'. To pass exception information, use the keyword argument exc_info with
a true value, e.g. logger.debug("Houston, we have a %s", "thorny problem", exc_info=1)
"""
if self.isEnabledFor(DEBUG):
self._log(DEBUG, msg, args, **kwargs) def info(self, msg, *args, **kwargs):
"""
Log 'msg % args' with severity 'INFO'. To pass exception information, use the keyword argument exc_info with
a true value, e.g. logger.info("Houston, we have a %s", "interesting problem", exc_info=1)
"""
if self.isEnabledFor(INFO):
self._log(INFO, msg, args, **kwargs) def warning(self, msg, *args, **kwargs):
"""
Log 'msg % args' with severity 'WARNING'. To pass exception information, use the keyword argument exc_info with
a true value, e.g. logger.warning("Houston, we have a %s", "bit of a problem", exc_info=1)
"""
if self.isEnabledFor(WARNING):
self._log(WARNING, msg, args, **kwargs) def warn(self, msg, *args, **kwargs):
warnings.warn("The 'warn' method is deprecated, "
"use 'warning' instead", DeprecationWarning, 2)
self.warning(msg, *args, **kwargs) def error(self, msg, *args, **kwargs):
"""
Log 'msg % args' with severity 'ERROR'. To pass exception information, use the keyword argument exc_info with
a true value, e.g. logger.error("Houston, we have a %s", "major problem", exc_info=1)
"""
if self.isEnabledFor(ERROR):
self._log(ERROR, msg, args, **kwargs) def exception(self, msg, *args, exc_info=True, **kwargs):
"""
Convenience method for logging an ERROR with exception information.
"""
self.error(msg, *args, exc_info=exc_info, **kwargs) def critical(self, msg, *args, **kwargs):
"""
Log 'msg % args' with severity 'CRITICAL'. To pass exception information, use the keyword argument exc_info with
a true value, e.g. logger.critical("Houston, we have a %s", "major disaster", exc_info=1)
"""
if self.isEnabledFor(CRITICAL):
self._log(CRITICAL, msg, args, **kwargs) fatal = critical def log(self, level, msg, *args, **kwargs):
"""
Log 'msg % args' with the integer severity 'level'. To pass exception information, use the keyword argument exc_info with
a true value, e.g. logger.log(level, "We have a %s", "mysterious problem", exc_info=1)
"""
if not isinstance(level, int):
if raiseExceptions:
raise TypeError("level must be an integer")
else:
return
if self.isEnabledFor(level):
self._log(level, msg, args, **kwargs) def findCaller(self, stack_info=False):
"""
Find the stack frame of the caller so that we can note the source
file name, line number and function name.
"""
f = currentframe()
#On some versions of IronPython, currentframe() returns None if
#IronPython isn't run with -X:Frames.
if f is not None:
f = f.f_back
rv = "(unknown file)", 0, "(unknown function)", None
while hasattr(f, "f_code"):
co = f.f_code
filename = os.path.normcase(co.co_filename)
if filename == _srcfile:
f = f.f_back
continue
sinfo = None
if stack_info:
sio = io.StringIO()
sio.write('Stack (most recent call last):\n')
traceback.print_stack(f, file=sio)
sinfo = sio.getvalue()
if sinfo[-1] == '\n':
sinfo = sinfo[:-1]
sio.close()
rv = (co.co_filename, f.f_lineno, co.co_name, sinfo)
break
return rv def makeRecord(self, name, level, fn, lno, msg, args, exc_info,
func=None, extra=None, sinfo=None):
"""
A factory method which can be overridden in subclasses to create
specialized LogRecords.
"""
rv = _logRecordFactory(name, level, fn, lno, msg, args, exc_info, func,
sinfo)
if extra is not None:
for key in extra:
if (key in ["message", "asctime"]) or (key in rv.__dict__):
raise KeyError("Attempt to overwrite %r in LogRecord" % key)
rv.__dict__[key] = extra[key]
return rv def _log(self, level, msg, args, exc_info=None, extra=None, stack_info=False):
"""
Low-level logging routine which creates a LogRecord and then calls
all the handlers of this logger to handle the record.
"""
sinfo = None
if _srcfile:
#IronPython doesn't track Python frames, so findCaller raises an
#exception on some versions of IronPython. We trap it here so that
#IronPython can use logging.
try:
fn, lno, func, sinfo = self.findCaller(stack_info)
except ValueError: # pragma: no cover
fn, lno, func = "(unknown file)", 0, "(unknown function)"
else: # pragma: no cover
fn, lno, func = "(unknown file)", 0, "(unknown function)"
if exc_info:
if isinstance(exc_info, BaseException):
exc_info = (type(exc_info), exc_info, exc_info.__traceback__)
elif not isinstance(exc_info, tuple):
exc_info = sys.exc_info()
record = self.makeRecord(self.name, level, fn, lno, msg, args,
exc_info, func, extra, sinfo)
self.handle(record) def handle(self, record):
"""
Call the handlers for the specified record. This method is used for unpickled records received from a socket, as
well as those created locally. Logger-level filtering is applied.
"""
if (not self.disabled) and self.filter(record):
self.callHandlers(record) def addHandler(self, hdlr):
"""
Add the specified handler to this logger.
"""
_acquireLock()
try:
if not (hdlr in self.handlers):
self.handlers.append(hdlr)
finally:
_releaseLock() def removeHandler(self, hdlr):
"""
Remove the specified handler from this logger.
"""
_acquireLock()
try:
if hdlr in self.handlers:
self.handlers.remove(hdlr)
finally:
_releaseLock() def hasHandlers(self):
"""
See if this logger has any handlers configured. Loop through all handlers for this logger and its parents in the
logger hierarchy. Return True if a handler was found, else False.
Stop searching up the hierarchy whenever a logger with the "propagate"
attribute set to zero is found - that will be the last logger which
is checked for the existence of handlers.
"""
c = self
rv = False
while c:
if c.handlers:
rv = True
break
if not c.propagate:
break
else:
c = c.parent
return rv def callHandlers(self, record):
"""
Pass a record to all relevant handlers. Loop through all handlers for this logger and its parents in the
logger hierarchy. If no handler was found, output a one-off error
message to sys.stderr. Stop searching up the hierarchy whenever a
logger with the "propagate" attribute set to zero is found - that
will be the last logger whose handlers are called.
"""
c = self
found = 0
while c:
for hdlr in c.handlers:
found = found + 1
if record.levelno >= hdlr.level:
hdlr.handle(record)
if not c.propagate:
c = None #break out
else:
c = c.parent
if (found == 0):
if lastResort:
if record.levelno >= lastResort.level:
lastResort.handle(record)
elif raiseExceptions and not self.manager.emittedNoHandlerWarning:
sys.stderr.write("No handlers could be found for logger"
" \"%s\"\n" % self.name)
self.manager.emittedNoHandlerWarning = True def getEffectiveLevel(self):
"""
Get the effective level for this logger. Loop through this logger and its parents in the logger hierarchy,
looking for a non-zero logging level. Return the first one found.
"""
logger = self
while logger:
if logger.level:
return logger.level
logger = logger.parent
return NOTSET def isEnabledFor(self, level):
"""
Is this logger enabled for level 'level'?
"""
if self.manager.disable >= level:
return False
return level >= self.getEffectiveLevel() def getChild(self, suffix):
"""
Get a logger which is a descendant to this one. This is a convenience method, such that logging.getLogger('abc').getChild('def.ghi') is the same as logging.getLogger('abc.def.ghi') It's useful, for example, when the parent logger is named using
__name__ rather than a literal string.
"""
if self.root is not self:
suffix = '.'.join((self.name, suffix))
return self.manager.getLogger(suffix) def __repr__(self):
level = getLevelName(self.getEffectiveLevel())
return '<%s %s (%s)>' % (self.__class__.__name__, self.name, level) class RootLogger(Logger):
"""
A root logger is not that different to any other logger, except that
it must have a logging level and there is only one instance of it in
the hierarchy.
"""
def __init__(self, level):
"""
Initialize the logger with the name "root".
"""
Logger.__init__(self, "root", level) _loggerClass = Logger class LoggerAdapter(object):
"""
An adapter for loggers which makes it easier to specify contextual
information in logging output.
""" def __init__(self, logger, extra):
"""
Initialize the adapter with a logger and a dict-like object which
provides contextual information. This constructor signature allows
easy stacking of LoggerAdapters, if so desired. You can effectively pass keyword arguments as shown in the
following example: adapter = LoggerAdapter(someLogger, dict(p1=v1, p2="v2"))
"""
self.logger = logger
self.extra = extra def process(self, msg, kwargs):
"""
Process the logging message and keyword arguments passed in to
a logging call to insert contextual information. You can either
manipulate the message itself, the keyword args or both. Return
the message and kwargs modified (or not) to suit your needs. Normally, you'll only need to override this one method in a
LoggerAdapter subclass for your specific needs.
"""
kwargs["extra"] = self.extra
return msg, kwargs #
# Boilerplate convenience methods
#
def debug(self, msg, *args, **kwargs):
"""
Delegate a debug call to the underlying logger.
"""
self.log(DEBUG, msg, *args, **kwargs) def info(self, msg, *args, **kwargs):
"""
Delegate an info call to the underlying logger.
"""
self.log(INFO, msg, *args, **kwargs) def warning(self, msg, *args, **kwargs):
"""
Delegate a warning call to the underlying logger.
"""
self.log(WARNING, msg, *args, **kwargs) def warn(self, msg, *args, **kwargs):
warnings.warn("The 'warn' method is deprecated, "
"use 'warning' instead", DeprecationWarning, 2)
self.warning(msg, *args, **kwargs) def error(self, msg, *args, **kwargs):
"""
Delegate an error call to the underlying logger.
"""
self.log(ERROR, msg, *args, **kwargs) def exception(self, msg, *args, exc_info=True, **kwargs):
"""
Delegate an exception call to the underlying logger.
"""
self.log(ERROR, msg, *args, exc_info=exc_info, **kwargs) def critical(self, msg, *args, **kwargs):
"""
Delegate a critical call to the underlying logger.
"""
self.log(CRITICAL, msg, *args, **kwargs) def log(self, level, msg, *args, **kwargs):
"""
Delegate a log call to the underlying logger, after adding
contextual information from this adapter instance.
"""
if self.isEnabledFor(level):
msg, kwargs = self.process(msg, kwargs)
self.logger.log(level, msg, *args, **kwargs) def isEnabledFor(self, level):
"""
Is this logger enabled for level 'level'?
"""
if self.logger.manager.disable >= level:
return False
return level >= self.getEffectiveLevel() def setLevel(self, level):
"""
Set the specified level on the underlying logger.
"""
self.logger.setLevel(level) def getEffectiveLevel(self):
"""
Get the effective level for the underlying logger.
"""
return self.logger.getEffectiveLevel() def hasHandlers(self):
"""
See if the underlying logger has any handlers.
"""
return self.logger.hasHandlers() def _log(self, level, msg, args, exc_info=None, extra=None, stack_info=False):
"""
Low-level log implementation, proxied to allow nested logger adapters.
"""
return self.logger._log(
level,
msg,
args,
exc_info=exc_info,
extra=extra,
stack_info=stack_info,
) @property
def manager(self):
return self.logger.manager @manager.setter
def manager(self, value):
self.logger.manager = value @property
def name(self):
return self.logger.name def __repr__(self):
logger = self.logger
level = getLevelName(logger.getEffectiveLevel())
return '<%s %s (%s)>' % (self.__class__.__name__, logger.name, level) root = RootLogger(WARNING)
Logger.root = root
Logger.manager = Manager(Logger.root) #---------------------------------------------------------------------------
# Configuration classes and functions
#--------------------------------------------------------------------------- def basicConfig(**kwargs):
"""
Do basic configuration for the logging system. This function does nothing if the root logger already has handlers
configured. It is a convenience method intended for use by simple scripts
to do one-shot configuration of the logging package. The default behaviour is to create a StreamHandler which writes to
sys.stderr, set a formatter using the BASIC_FORMAT format string, and
add the handler to the root logger. A number of optional keyword arguments may be specified, which can alter
the default behaviour. filename Specifies that a FileHandler be created, using the specified
filename, rather than a StreamHandler.
filemode Specifies the mode to open the file, if filename is specified
(if filemode is unspecified, it defaults to 'a').
format Use the specified format string for the handler.
datefmt Use the specified date/time format.
style If a format string is specified, use this to specify the
type of format string (possible values '%', '{', '$', for
%-formatting, :meth:`str.format` and :class:`string.Template`
- defaults to '%').
level Set the root logger level to the specified level.
stream Use the specified stream to initialize the StreamHandler. Note
that this argument is incompatible with 'filename' - if both
are present, 'stream' is ignored.
handlers If specified, this should be an iterable of already created
handlers, which will be added to the root handler. Any handler
in the list which does not have a formatter assigned will be
assigned the formatter created in this function. Note that you could specify a stream created using open(filename, mode)
rather than passing the filename and mode in. However, it should be
remembered that StreamHandler does not close its stream (since it may be
using sys.stdout or sys.stderr), whereas FileHandler closes its stream
when the handler is closed. .. versionchanged:: 3.2
Added the ``style`` parameter. .. versionchanged:: 3.3
Added the ``handlers`` parameter. A ``ValueError`` is now thrown for
incompatible arguments (e.g. ``handlers`` specified together with
``filename``/``filemode``, or ``filename``/``filemode`` specified
together with ``stream``, or ``handlers`` specified together with
``stream``.
"""
# Add thread safety in case someone mistakenly calls
# basicConfig() from multiple threads
_acquireLock()
try:
if len(root.handlers) == 0:
handlers = kwargs.pop("handlers", None)
if handlers is None:
if "stream" in kwargs and "filename" in kwargs:
raise ValueError("'stream' and 'filename' should not be "
"specified together")
else:
if "stream" in kwargs or "filename" in kwargs:
raise ValueError("'stream' or 'filename' should not be "
"specified together with 'handlers'")
if handlers is None:
filename = kwargs.pop("filename", None)
mode = kwargs.pop("filemode", 'a')
if filename:
h = FileHandler(filename, mode)
else:
stream = kwargs.pop("stream", None)
h = StreamHandler(stream)
handlers = [h]
dfs = kwargs.pop("datefmt", None)
style = kwargs.pop("style", '%')
if style not in _STYLES:
raise ValueError('Style must be one of: %s' % ','.join(
_STYLES.keys()))
fs = kwargs.pop("format", _STYLES[style][1])
fmt = Formatter(fs, dfs, style)
for h in handlers:
if h.formatter is None:
h.setFormatter(fmt)
root.addHandler(h)
level = kwargs.pop("level", None)
if level is not None:
root.setLevel(level)
if kwargs:
keys = ', '.join(kwargs.keys())
raise ValueError('Unrecognised argument(s): %s' % keys)
finally:
_releaseLock() #---------------------------------------------------------------------------
# Utility functions at module level.
# Basically delegate everything to the root logger.
#--------------------------------------------------------------------------- def getLogger(name=None):
"""
Return a logger with the specified name, creating it if necessary. If no name is specified, return the root logger.
"""
if name:
return Logger.manager.getLogger(name)
else:
return root def critical(msg, *args, **kwargs):
"""
Log a message with severity 'CRITICAL' on the root logger. If the logger
has no handlers, call basicConfig() to add a console handler with a
pre-defined format.
"""
if len(root.handlers) == 0:
basicConfig()
root.critical(msg, *args, **kwargs) fatal = critical def error(msg, *args, **kwargs):
"""
Log a message with severity 'ERROR' on the root logger. If the logger has
no handlers, call basicConfig() to add a console handler with a pre-defined
format.
"""
if len(root.handlers) == 0:
basicConfig()
root.error(msg, *args, **kwargs) def exception(msg, *args, exc_info=True, **kwargs):
"""
Log a message with severity 'ERROR' on the root logger, with exception
information. If the logger has no handlers, basicConfig() is called to add
a console handler with a pre-defined format.
"""
error(msg, *args, exc_info=exc_info, **kwargs) def warning(msg, *args, **kwargs):
"""
Log a message with severity 'WARNING' on the root logger. If the logger has
no handlers, call basicConfig() to add a console handler with a pre-defined
format.
"""
if len(root.handlers) == 0:
basicConfig()
root.warning(msg, *args, **kwargs) def warn(msg, *args, **kwargs):
warnings.warn("The 'warn' function is deprecated, "
"use 'warning' instead", DeprecationWarning, 2)
warning(msg, *args, **kwargs) def info(msg, *args, **kwargs):
"""
Log a message with severity 'INFO' on the root logger. If the logger has
no handlers, call basicConfig() to add a console handler with a pre-defined
format.
"""
if len(root.handlers) == 0:
basicConfig()
root.info(msg, *args, **kwargs) def debug(msg, *args, **kwargs):
"""
Log a message with severity 'DEBUG' on the root logger. If the logger has
no handlers, call basicConfig() to add a console handler with a pre-defined
format.
"""
if len(root.handlers) == 0:
basicConfig()
root.debug(msg, *args, **kwargs) def log(level, msg, *args, **kwargs):
"""
Log 'msg % args' with the integer severity 'level' on the root logger. If
the logger has no handlers, call basicConfig() to add a console handler
with a pre-defined format.
"""
if len(root.handlers) == 0:
basicConfig()
root.log(level, msg, *args, **kwargs) def disable(level):
"""
Disable all logging calls of severity 'level' and below.
"""
root.manager.disable = level def shutdown(handlerList=_handlerList):
"""
Perform any cleanup actions in the logging system (e.g. flushing
buffers). Should be called at application exit.
"""
for wr in reversed(handlerList[:]):
#errors might occur, for example, if files are locked
#we just ignore them if raiseExceptions is not set
try:
h = wr()
if h:
try:
h.acquire()
h.flush()
h.close()
except (OSError, ValueError):
# Ignore errors which might be caused
# because handlers have been closed but
# references to them are still around at
# application exit.
pass
finally:
h.release()
except: # ignore everything, as we're shutting down
if raiseExceptions:
raise
#else, swallow #Let's try and shutdown automatically on application exit...
import atexit
atexit.register(shutdown) # Null handler class NullHandler(Handler):
"""
This handler does nothing. It's intended to be used to avoid the
"No handlers could be found for logger XXX" one-off warning. This is
important for library code, which may contain code to log events. If a user
of the library does not configure logging, the one-off warning might be
produced; to avoid this, the library developer simply needs to instantiate
a NullHandler and add it to the top-level logger of the library module or
package.
"""
def handle(self, record):
"""Stub.""" def emit(self, record):
"""Stub.""" def createLock(self):
self.lock = None # Warnings integration _warnings_showwarning = None def _showwarning(message, category, filename, lineno, file=None, line=None):
"""
Implementation of showwarnings which redirects to logging, which will first
check to see if the file parameter is None. If a file is specified, it will
delegate to the original warnings implementation of showwarning. Otherwise,
it will call warnings.formatwarning and will log the resulting string to a
warnings logger named "py.warnings" with level logging.WARNING.
"""
if file is not None:
if _warnings_showwarning is not None:
_warnings_showwarning(message, category, filename, lineno, file, line)
else:
s = warnings.formatwarning(message, category, filename, lineno, line)
logger = getLogger("py.warnings")
if not logger.handlers:
logger.addHandler(NullHandler())
logger.warning("%s", s) def captureWarnings(capture):
"""
If capture is true, redirect all warnings to the logging package.
If capture is False, ensure that warnings are not redirected to logging
but to their original destinations.
"""
global _warnings_showwarning
if capture:
if _warnings_showwarning is None:
_warnings_showwarning = warnings.showwarning
warnings.showwarning = _showwarning
else:
if _warnings_showwarning is not None:
warnings.showwarning = _warnings_showwarning
_warnings_showwarning = None
__init__.py
# Copyright 2001-2014 by Vinay Sajip. All Rights Reserved.
#
# Permission to use, copy, modify, and distribute this software and its
# documentation for any purpose and without fee is hereby granted,
# provided that the above copyright notice appear in all copies and that
# both that copyright notice and this permission notice appear in
# supporting documentation, and that the name of Vinay Sajip
# not be used in advertising or publicity pertaining to distribution
# of the software without specific, written prior permission.
# VINAY SAJIP DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
# ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
# VINAY SAJIP BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
# ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
# IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. """
Configuration functions for the logging package for Python. The core package
is based on PEP 282 and comments thereto in comp.lang.python, and influenced
by Apache's log4j system. Copyright (C) 2001-2014 Vinay Sajip. All Rights Reserved. To use, simply 'import logging' and log away!
""" import errno
import io
import logging
import logging.handlers
import re
import struct
import sys
import traceback try:
import _thread as thread
import threading
except ImportError: #pragma: no cover
thread = None from socketserver import ThreadingTCPServer, StreamRequestHandler DEFAULT_LOGGING_CONFIG_PORT = 9030 RESET_ERROR = errno.ECONNRESET #
# The following code implements a socket listener for on-the-fly
# reconfiguration of logging.
#
# _listener holds the server object doing the listening
_listener = None def fileConfig(fname, defaults=None, disable_existing_loggers=True):
"""
Read the logging configuration from a ConfigParser-format file. This can be called several times from an application, allowing an end user
the ability to select from various pre-canned configurations (if the
developer provides a mechanism to present the choices and load the chosen
configuration).
"""
import configparser if isinstance(fname, configparser.RawConfigParser):
cp = fname
else:
cp = configparser.ConfigParser(defaults)
if hasattr(fname, 'readline'):
cp.read_file(fname)
else:
cp.read(fname) formatters = _create_formatters(cp) # critical section
logging._acquireLock()
try:
logging._handlers.clear()
del logging._handlerList[:]
# Handlers add themselves to logging._handlers
handlers = _install_handlers(cp, formatters)
_install_loggers(cp, handlers, disable_existing_loggers)
finally:
logging._releaseLock() def _resolve(name):
"""Resolve a dotted name to a global object."""
name = name.split('.')
used = name.pop(0)
found = __import__(used)
for n in name:
used = used + '.' + n
try:
found = getattr(found, n)
except AttributeError:
__import__(used)
found = getattr(found, n)
return found def _strip_spaces(alist):
return map(lambda x: x.strip(), alist) def _create_formatters(cp):
"""Create and return formatters"""
flist = cp["formatters"]["keys"]
if not len(flist):
return {}
flist = flist.split(",")
flist = _strip_spaces(flist)
formatters = {}
for form in flist:
sectname = "formatter_%s" % form
fs = cp.get(sectname, "format", raw=True, fallback=None)
dfs = cp.get(sectname, "datefmt", raw=True, fallback=None)
stl = cp.get(sectname, "style", raw=True, fallback='%')
c = logging.Formatter
class_name = cp[sectname].get("class")
if class_name:
c = _resolve(class_name)
f = c(fs, dfs, stl)
formatters[form] = f
return formatters def _install_handlers(cp, formatters):
"""Install and return handlers"""
hlist = cp["handlers"]["keys"]
if not len(hlist):
return {}
hlist = hlist.split(",")
hlist = _strip_spaces(hlist)
handlers = {}
fixups = [] #for inter-handler references
for hand in hlist:
section = cp["handler_%s" % hand]
klass = section["class"]
fmt = section.get("formatter", "")
try:
klass = eval(klass, vars(logging))
except (AttributeError, NameError):
klass = _resolve(klass)
args = section["args"]
args = eval(args, vars(logging))
h = klass(*args)
if "level" in section:
level = section["level"]
h.setLevel(level)
if len(fmt):
h.setFormatter(formatters[fmt])
if issubclass(klass, logging.handlers.MemoryHandler):
target = section.get("target", "")
if len(target): #the target handler may not be loaded yet, so keep for later...
fixups.append((h, target))
handlers[hand] = h
#now all handlers are loaded, fixup inter-handler references...
for h, t in fixups:
h.setTarget(handlers[t])
return handlers def _handle_existing_loggers(existing, child_loggers, disable_existing):
"""
When (re)configuring logging, handle loggers which were in the previous
configuration but are not in the new configuration. There's no point
deleting them as other threads may continue to hold references to them;
and by disabling them, you stop them doing any logging. However, don't disable children of named loggers, as that's probably not
what was intended by the user. Also, allow existing loggers to NOT be
disabled if disable_existing is false.
"""
root = logging.root
for log in existing:
logger = root.manager.loggerDict[log]
if log in child_loggers:
logger.level = logging.NOTSET
logger.handlers = []
logger.propagate = True
else:
logger.disabled = disable_existing def _install_loggers(cp, handlers, disable_existing):
"""Create and install loggers""" # configure the root first
llist = cp["loggers"]["keys"]
llist = llist.split(",")
llist = list(map(lambda x: x.strip(), llist))
llist.remove("root")
section = cp["logger_root"]
root = logging.root
log = root
if "level" in section:
level = section["level"]
log.setLevel(level)
for h in root.handlers[:]:
root.removeHandler(h)
hlist = section["handlers"]
if len(hlist):
hlist = hlist.split(",")
hlist = _strip_spaces(hlist)
for hand in hlist:
log.addHandler(handlers[hand]) #and now the others...
#we don't want to lose the existing loggers,
#since other threads may have pointers to them.
#existing is set to contain all existing loggers,
#and as we go through the new configuration we
#remove any which are configured. At the end,
#what's left in existing is the set of loggers
#which were in the previous configuration but
#which are not in the new configuration.
existing = list(root.manager.loggerDict.keys())
#The list needs to be sorted so that we can
#avoid disabling child loggers of explicitly
#named loggers. With a sorted list it is easier
#to find the child loggers.
existing.sort()
#We'll keep the list of existing loggers
#which are children of named loggers here...
child_loggers = []
#now set up the new ones...
for log in llist:
section = cp["logger_%s" % log]
qn = section["qualname"]
propagate = section.getint("propagate", fallback=1)
logger = logging.getLogger(qn)
if qn in existing:
i = existing.index(qn) + 1 # start with the entry after qn
prefixed = qn + "."
pflen = len(prefixed)
num_existing = len(existing)
while i < num_existing:
if existing[i][:pflen] == prefixed:
child_loggers.append(existing[i])
i += 1
existing.remove(qn)
if "level" in section:
level = section["level"]
logger.setLevel(level)
for h in logger.handlers[:]:
logger.removeHandler(h)
logger.propagate = propagate
logger.disabled = 0
hlist = section["handlers"]
if len(hlist):
hlist = hlist.split(",")
hlist = _strip_spaces(hlist)
for hand in hlist:
logger.addHandler(handlers[hand]) #Disable any old loggers. There's no point deleting
#them as other threads may continue to hold references
#and by disabling them, you stop them doing any logging.
#However, don't disable children of named loggers, as that's
#probably not what was intended by the user.
#for log in existing:
# logger = root.manager.loggerDict[log]
# if log in child_loggers:
# logger.level = logging.NOTSET
# logger.handlers = []
# logger.propagate = 1
# elif disable_existing_loggers:
# logger.disabled = 1
_handle_existing_loggers(existing, child_loggers, disable_existing) IDENTIFIER = re.compile('^[a-z_][a-z0-9_]*$', re.I) def valid_ident(s):
m = IDENTIFIER.match(s)
if not m:
raise ValueError('Not a valid Python identifier: %r' % s)
return True class ConvertingMixin(object):
"""For ConvertingXXX's, this mixin class provides common functions""" def convert_with_key(self, key, value, replace=True):
result = self.configurator.convert(value)
#If the converted value is different, save for next time
if value is not result:
if replace:
self[key] = result
if type(result) in (ConvertingDict, ConvertingList,
ConvertingTuple):
result.parent = self
result.key = key
return result def convert(self, value):
result = self.configurator.convert(value)
if value is not result:
if type(result) in (ConvertingDict, ConvertingList,
ConvertingTuple):
result.parent = self
return result # The ConvertingXXX classes are wrappers around standard Python containers,
# and they serve to convert any suitable values in the container. The
# conversion converts base dicts, lists and tuples to their wrapped
# equivalents, whereas strings which match a conversion format are converted
# appropriately.
#
# Each wrapper should have a configurator attribute holding the actual
# configurator to use for conversion. class ConvertingDict(dict, ConvertingMixin):
"""A converting dictionary wrapper.""" def __getitem__(self, key):
value = dict.__getitem__(self, key)
return self.convert_with_key(key, value) def get(self, key, default=None):
value = dict.get(self, key, default)
return self.convert_with_key(key, value) def pop(self, key, default=None):
value = dict.pop(self, key, default)
return self.convert_with_key(key, value, replace=False) class ConvertingList(list, ConvertingMixin):
"""A converting list wrapper."""
def __getitem__(self, key):
value = list.__getitem__(self, key)
return self.convert_with_key(key, value) def pop(self, idx=-1):
value = list.pop(self, idx)
return self.convert(value) class ConvertingTuple(tuple, ConvertingMixin):
"""A converting tuple wrapper."""
def __getitem__(self, key):
value = tuple.__getitem__(self, key)
# Can't replace a tuple entry.
return self.convert_with_key(key, value, replace=False) class BaseConfigurator(object):
"""
The configurator base class which defines some useful defaults.
""" CONVERT_PATTERN = re.compile(r'^(?P<prefix>[a-z]+)://(?P<suffix>.*)$') WORD_PATTERN = re.compile(r'^\s*(\w+)\s*')
DOT_PATTERN = re.compile(r'^\.\s*(\w+)\s*')
INDEX_PATTERN = re.compile(r'^\[\s*(\w+)\s*\]\s*')
DIGIT_PATTERN = re.compile(r'^\d+$') value_converters = {
'ext' : 'ext_convert',
'cfg' : 'cfg_convert',
} # We might want to use a different one, e.g. importlib
importer = staticmethod(__import__) def __init__(self, config):
self.config = ConvertingDict(config)
self.config.configurator = self def resolve(self, s):
"""
Resolve strings to objects using standard import and attribute
syntax.
"""
name = s.split('.')
used = name.pop(0)
try:
found = self.importer(used)
for frag in name:
used += '.' + frag
try:
found = getattr(found, frag)
except AttributeError:
self.importer(used)
found = getattr(found, frag)
return found
except ImportError:
e, tb = sys.exc_info()[1:]
v = ValueError('Cannot resolve %r: %s' % (s, e))
v.__cause__, v.__traceback__ = e, tb
raise v def ext_convert(self, value):
"""Default converter for the ext:// protocol."""
return self.resolve(value) def cfg_convert(self, value):
"""Default converter for the cfg:// protocol."""
rest = value
m = self.WORD_PATTERN.match(rest)
if m is None:
raise ValueError("Unable to convert %r" % value)
else:
rest = rest[m.end():]
d = self.config[m.groups()[0]]
#print d, rest
while rest:
m = self.DOT_PATTERN.match(rest)
if m:
d = d[m.groups()[0]]
else:
m = self.INDEX_PATTERN.match(rest)
if m:
idx = m.groups()[0]
if not self.DIGIT_PATTERN.match(idx):
d = d[idx]
else:
try:
n = int(idx) # try as number first (most likely)
d = d[n]
except TypeError:
d = d[idx]
if m:
rest = rest[m.end():]
else:
raise ValueError('Unable to convert '
'%r at %r' % (value, rest))
#rest should be empty
return d def convert(self, value):
"""
Convert values to an appropriate type. dicts, lists and tuples are
replaced by their converting alternatives. Strings are checked to
see if they have a conversion format and are converted if they do.
"""
if not isinstance(value, ConvertingDict) and isinstance(value, dict):
value = ConvertingDict(value)
value.configurator = self
elif not isinstance(value, ConvertingList) and isinstance(value, list):
value = ConvertingList(value)
value.configurator = self
elif not isinstance(value, ConvertingTuple) and\
isinstance(value, tuple):
value = ConvertingTuple(value)
value.configurator = self
elif isinstance(value, str): # str for py3k
m = self.CONVERT_PATTERN.match(value)
if m:
d = m.groupdict()
prefix = d['prefix']
converter = self.value_converters.get(prefix, None)
if converter:
suffix = d['suffix']
converter = getattr(self, converter)
value = converter(suffix)
return value def configure_custom(self, config):
"""Configure an object with a user-supplied factory."""
c = config.pop('()')
if not callable(c):
c = self.resolve(c)
props = config.pop('.', None)
# Check for valid identifiers
kwargs = dict([(k, config[k]) for k in config if valid_ident(k)])
result = c(**kwargs)
if props:
for name, value in props.items():
setattr(result, name, value)
return result def as_tuple(self, value):
"""Utility function which converts lists to tuples."""
if isinstance(value, list):
value = tuple(value)
return value class DictConfigurator(BaseConfigurator):
"""
Configure logging using a dictionary-like object to describe the
configuration.
""" def configure(self):
"""Do the configuration.""" config = self.config
if 'version' not in config:
raise ValueError("dictionary doesn't specify a version")
if config['version'] != 1:
raise ValueError("Unsupported version: %s" % config['version'])
incremental = config.pop('incremental', False)
EMPTY_DICT = {}
logging._acquireLock()
try:
if incremental:
handlers = config.get('handlers', EMPTY_DICT)
for name in handlers:
if name not in logging._handlers:
raise ValueError('No handler found with '
'name %r' % name)
else:
try:
handler = logging._handlers[name]
handler_config = handlers[name]
level = handler_config.get('level', None)
if level:
handler.setLevel(logging._checkLevel(level))
except Exception as e:
raise ValueError('Unable to configure handler '
'%r: %s' % (name, e))
loggers = config.get('loggers', EMPTY_DICT)
for name in loggers:
try:
self.configure_logger(name, loggers[name], True)
except Exception as e:
raise ValueError('Unable to configure logger '
'%r: %s' % (name, e))
root = config.get('root', None)
if root:
try:
self.configure_root(root, True)
except Exception as e:
raise ValueError('Unable to configure root '
'logger: %s' % e)
else:
disable_existing = config.pop('disable_existing_loggers', True) logging._handlers.clear()
del logging._handlerList[:] # Do formatters first - they don't refer to anything else
formatters = config.get('formatters', EMPTY_DICT)
for name in formatters:
try:
formatters[name] = self.configure_formatter(
formatters[name])
except Exception as e:
raise ValueError('Unable to configure '
'formatter %r: %s' % (name, e))
# Next, do filters - they don't refer to anything else, either
filters = config.get('filters', EMPTY_DICT)
for name in filters:
try:
filters[name] = self.configure_filter(filters[name])
except Exception as e:
raise ValueError('Unable to configure '
'filter %r: %s' % (name, e)) # Next, do handlers - they refer to formatters and filters
# As handlers can refer to other handlers, sort the keys
# to allow a deterministic order of configuration
handlers = config.get('handlers', EMPTY_DICT)
deferred = []
for name in sorted(handlers):
try:
handler = self.configure_handler(handlers[name])
handler.name = name
handlers[name] = handler
except Exception as e:
if 'target not configured yet' in str(e):
deferred.append(name)
else:
raise ValueError('Unable to configure handler '
'%r: %s' % (name, e)) # Now do any that were deferred
for name in deferred:
try:
handler = self.configure_handler(handlers[name])
handler.name = name
handlers[name] = handler
except Exception as e:
raise ValueError('Unable to configure handler '
'%r: %s' % (name, e)) # Next, do loggers - they refer to handlers and filters #we don't want to lose the existing loggers,
#since other threads may have pointers to them.
#existing is set to contain all existing loggers,
#and as we go through the new configuration we
#remove any which are configured. At the end,
#what's left in existing is the set of loggers
#which were in the previous configuration but
#which are not in the new configuration.
root = logging.root
existing = list(root.manager.loggerDict.keys())
#The list needs to be sorted so that we can
#avoid disabling child loggers of explicitly
#named loggers. With a sorted list it is easier
#to find the child loggers.
existing.sort()
#We'll keep the list of existing loggers
#which are children of named loggers here...
child_loggers = []
#now set up the new ones...
loggers = config.get('loggers', EMPTY_DICT)
for name in loggers:
if name in existing:
i = existing.index(name) + 1 # look after name
prefixed = name + "."
pflen = len(prefixed)
num_existing = len(existing)
while i < num_existing:
if existing[i][:pflen] == prefixed:
child_loggers.append(existing[i])
i += 1
existing.remove(name)
try:
self.configure_logger(name, loggers[name])
except Exception as e:
raise ValueError('Unable to configure logger '
'%r: %s' % (name, e)) #Disable any old loggers. There's no point deleting
#them as other threads may continue to hold references
#and by disabling them, you stop them doing any logging.
#However, don't disable children of named loggers, as that's
#probably not what was intended by the user.
#for log in existing:
# logger = root.manager.loggerDict[log]
# if log in child_loggers:
# logger.level = logging.NOTSET
# logger.handlers = []
# logger.propagate = True
# elif disable_existing:
# logger.disabled = True
_handle_existing_loggers(existing, child_loggers,
disable_existing) # And finally, do the root logger
root = config.get('root', None)
if root:
try:
self.configure_root(root)
except Exception as e:
raise ValueError('Unable to configure root '
'logger: %s' % e)
finally:
logging._releaseLock() def configure_formatter(self, config):
"""Configure a formatter from a dictionary."""
if '()' in config:
factory = config['()'] # for use in exception handler
try:
result = self.configure_custom(config)
except TypeError as te:
if "'format'" not in str(te):
raise
#Name of parameter changed from fmt to format.
#Retry with old name.
#This is so that code can be used with older Python versions
#(e.g. by Django)
config['fmt'] = config.pop('format')
config['()'] = factory
result = self.configure_custom(config)
else:
fmt = config.get('format', None)
dfmt = config.get('datefmt', None)
style = config.get('style', '%')
cname = config.get('class', None)
if not cname:
c = logging.Formatter
else:
c = _resolve(cname)
result = c(fmt, dfmt, style)
return result def configure_filter(self, config):
"""Configure a filter from a dictionary."""
if '()' in config:
result = self.configure_custom(config)
else:
name = config.get('name', '')
result = logging.Filter(name)
return result def add_filters(self, filterer, filters):
"""Add filters to a filterer from a list of names."""
for f in filters:
try:
filterer.addFilter(self.config['filters'][f])
except Exception as e:
raise ValueError('Unable to add filter %r: %s' % (f, e)) def configure_handler(self, config):
"""Configure a handler from a dictionary."""
config_copy = dict(config) # for restoring in case of error
formatter = config.pop('formatter', None)
if formatter:
try:
formatter = self.config['formatters'][formatter]
except Exception as e:
raise ValueError('Unable to set formatter '
'%r: %s' % (formatter, e))
level = config.pop('level', None)
filters = config.pop('filters', None)
if '()' in config:
c = config.pop('()')
if not callable(c):
c = self.resolve(c)
factory = c
else:
cname = config.pop('class')
klass = self.resolve(cname)
#Special case for handler which refers to another handler
if issubclass(klass, logging.handlers.MemoryHandler) and\
'target' in config:
try:
th = self.config['handlers'][config['target']]
if not isinstance(th, logging.Handler):
config.update(config_copy) # restore for deferred cfg
raise TypeError('target not configured yet')
config['target'] = th
except Exception as e:
raise ValueError('Unable to set target handler '
'%r: %s' % (config['target'], e))
elif issubclass(klass, logging.handlers.SMTPHandler) and\
'mailhost' in config:
config['mailhost'] = self.as_tuple(config['mailhost'])
elif issubclass(klass, logging.handlers.SysLogHandler) and\
'address' in config:
config['address'] = self.as_tuple(config['address'])
factory = klass
props = config.pop('.', None)
kwargs = dict([(k, config[k]) for k in config if valid_ident(k)])
try:
result = factory(**kwargs)
except TypeError as te:
if "'stream'" not in str(te):
raise
#The argument name changed from strm to stream
#Retry with old name.
#This is so that code can be used with older Python versions
#(e.g. by Django)
kwargs['strm'] = kwargs.pop('stream')
result = factory(**kwargs)
if formatter:
result.setFormatter(formatter)
if level is not None:
result.setLevel(logging._checkLevel(level))
if filters:
self.add_filters(result, filters)
if props:
for name, value in props.items():
setattr(result, name, value)
return result def add_handlers(self, logger, handlers):
"""Add handlers to a logger from a list of names."""
for h in handlers:
try:
logger.addHandler(self.config['handlers'][h])
except Exception as e:
raise ValueError('Unable to add handler %r: %s' % (h, e)) def common_logger_config(self, logger, config, incremental=False):
"""
Perform configuration which is common to root and non-root loggers.
"""
level = config.get('level', None)
if level is not None:
logger.setLevel(logging._checkLevel(level))
if not incremental:
#Remove any existing handlers
for h in logger.handlers[:]:
logger.removeHandler(h)
handlers = config.get('handlers', None)
if handlers:
self.add_handlers(logger, handlers)
filters = config.get('filters', None)
if filters:
self.add_filters(logger, filters) def configure_logger(self, name, config, incremental=False):
"""Configure a non-root logger from a dictionary."""
logger = logging.getLogger(name)
self.common_logger_config(logger, config, incremental)
propagate = config.get('propagate', None)
if propagate is not None:
logger.propagate = propagate def configure_root(self, config, incremental=False):
"""Configure a root logger from a dictionary."""
root = logging.getLogger()
self.common_logger_config(root, config, incremental) dictConfigClass = DictConfigurator def dictConfig(config):
"""Configure logging using a dictionary."""
dictConfigClass(config).configure() def listen(port=DEFAULT_LOGGING_CONFIG_PORT, verify=None):
"""
Start up a socket server on the specified port, and listen for new
configurations. These will be sent as a file suitable for processing by fileConfig().
Returns a Thread object on which you can call start() to start the server,
and which you can join() when appropriate. To stop the server, call
stopListening(). Use the ``verify`` argument to verify any bytes received across the wire
from a client. If specified, it should be a callable which receives a
single argument - the bytes of configuration data received across the
network - and it should return either ``None``, to indicate that the
passed in bytes could not be verified and should be discarded, or a
byte string which is then passed to the configuration machinery as
normal. Note that you can return transformed bytes, e.g. by decrypting
the bytes passed in.
"""
if not thread: #pragma: no cover
raise NotImplementedError("listen() needs threading to work") class ConfigStreamHandler(StreamRequestHandler):
"""
Handler for a logging configuration request. It expects a completely new logging configuration and uses fileConfig
to install it.
"""
def handle(self):
"""
Handle a request. Each request is expected to be a 4-byte length, packed using
struct.pack(">L", n), followed by the config file.
Uses fileConfig() to do the grunt work.
"""
try:
conn = self.connection
chunk = conn.recv(4)
if len(chunk) == 4:
slen = struct.unpack(">L", chunk)[0]
chunk = self.connection.recv(slen)
while len(chunk) < slen:
chunk = chunk + conn.recv(slen - len(chunk))
if self.server.verify is not None:
chunk = self.server.verify(chunk)
if chunk is not None: # verified, can process
chunk = chunk.decode("utf-8")
try:
import json
d =json.loads(chunk)
assert isinstance(d, dict)
dictConfig(d)
except Exception:
#Apply new configuration. file = io.StringIO(chunk)
try:
fileConfig(file)
except Exception:
traceback.print_exc()
if self.server.ready:
self.server.ready.set()
except OSError as e:
if e.errno != RESET_ERROR:
raise class ConfigSocketReceiver(ThreadingTCPServer):
"""
A simple TCP socket-based logging config receiver.
""" allow_reuse_address = 1 def __init__(self, host='localhost', port=DEFAULT_LOGGING_CONFIG_PORT,
handler=None, ready=None, verify=None):
ThreadingTCPServer.__init__(self, (host, port), handler)
logging._acquireLock()
self.abort = 0
logging._releaseLock()
self.timeout = 1
self.ready = ready
self.verify = verify def serve_until_stopped(self):
import select
abort = 0
while not abort:
rd, wr, ex = select.select([self.socket.fileno()],
[], [],
self.timeout)
if rd:
self.handle_request()
logging._acquireLock()
abort = self.abort
logging._releaseLock()
self.socket.close() class Server(threading.Thread): def __init__(self, rcvr, hdlr, port, verify):
super(Server, self).__init__()
self.rcvr = rcvr
self.hdlr = hdlr
self.port = port
self.verify = verify
self.ready = threading.Event() def run(self):
server = self.rcvr(port=self.port, handler=self.hdlr,
ready=self.ready,
verify=self.verify)
if self.port == 0:
self.port = server.server_address[1]
self.ready.set()
global _listener
logging._acquireLock()
_listener = server
logging._releaseLock()
server.serve_until_stopped() return Server(ConfigSocketReceiver, ConfigStreamHandler, port, verify) def stopListening():
"""
Stop the listening server which was created with a call to listen().
"""
global _listener
logging._acquireLock()
try:
if _listener:
_listener.abort = 1
_listener = None
finally:
logging._releaseLock()
config.py
# Copyright 2001-2016 by Vinay Sajip. All Rights Reserved.
#
# Permission to use, copy, modify, and distribute this software and its
# documentation for any purpose and without fee is hereby granted,
# provided that the above copyright notice appear in all copies and that
# both that copyright notice and this permission notice appear in
# supporting documentation, and that the name of Vinay Sajip
# not be used in advertising or publicity pertaining to distribution
# of the software without specific, written prior permission.
# VINAY SAJIP DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
# ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
# VINAY SAJIP BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
# ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
# IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. """
Additional handlers for the logging package for Python. The core package is
based on PEP 282 and comments thereto in comp.lang.python. Copyright (C) 2001-2016 Vinay Sajip. All Rights Reserved. To use, simply 'import logging.handlers' and log away!
""" import logging, socket, os, pickle, struct, time, re
from stat import ST_DEV, ST_INO, ST_MTIME
import queue
try:
import threading
except ImportError: #pragma: no cover
threading = None #
# Some constants...
# DEFAULT_TCP_LOGGING_PORT = 9020
DEFAULT_UDP_LOGGING_PORT = 9021
DEFAULT_HTTP_LOGGING_PORT = 9022
DEFAULT_SOAP_LOGGING_PORT = 9023
SYSLOG_UDP_PORT = 514
SYSLOG_TCP_PORT = 514 _MIDNIGHT = 24 * 60 * 60 # number of seconds in a day class BaseRotatingHandler(logging.FileHandler):
"""
Base class for handlers that rotate log files at a certain point.
Not meant to be instantiated directly. Instead, use RotatingFileHandler
or TimedRotatingFileHandler.
"""
def __init__(self, filename, mode, encoding=None, delay=False):
"""
Use the specified filename for streamed logging
"""
logging.FileHandler.__init__(self, filename, mode, encoding, delay)
self.mode = mode
self.encoding = encoding
self.namer = None
self.rotator = None def emit(self, record):
"""
Emit a record. Output the record to the file, catering for rollover as described
in doRollover().
"""
try:
if self.shouldRollover(record):
self.doRollover()
logging.FileHandler.emit(self, record)
except Exception:
self.handleError(record) def rotation_filename(self, default_name):
"""
Modify the filename of a log file when rotating. This is provided so that a custom filename can be provided. The default implementation calls the 'namer' attribute of the
handler, if it's callable, passing the default name to
it. If the attribute isn't callable (the default is None), the name
is returned unchanged. :param default_name: The default name for the log file.
"""
if not callable(self.namer):
result = default_name
else:
result = self.namer(default_name)
return result def rotate(self, source, dest):
"""
When rotating, rotate the current log. The default implementation calls the 'rotator' attribute of the
handler, if it's callable, passing the source and dest arguments to
it. If the attribute isn't callable (the default is None), the source
is simply renamed to the destination. :param source: The source filename. This is normally the base
filename, e.g. 'test.log'
:param dest: The destination filename. This is normally
what the source is rotated to, e.g. 'test.log.1'.
"""
if not callable(self.rotator):
# Issue 18940: A file may not have been created if delay is True.
if os.path.exists(source):
os.rename(source, dest)
else:
self.rotator(source, dest) class RotatingFileHandler(BaseRotatingHandler):
"""
Handler for logging to a set of files, which switches from one file
to the next when the current file reaches a certain size.
"""
def __init__(self, filename, mode='a', maxBytes=0, backupCount=0, encoding=None, delay=False):
"""
Open the specified file and use it as the stream for logging. By default, the file grows indefinitely. You can specify particular
values of maxBytes and backupCount to allow the file to rollover at
a predetermined size. Rollover occurs whenever the current log file is nearly maxBytes in
length. If backupCount is >= 1, the system will successively create
new files with the same pathname as the base file, but with extensions
".1", ".2" etc. appended to it. For example, with a backupCount of 5
and a base file name of "app.log", you would get "app.log",
"app.log.1", "app.log.2", ... through to "app.log.5". The file being
written to is always "app.log" - when it gets filled up, it is closed
and renamed to "app.log.1", and if files "app.log.1", "app.log.2" etc.
exist, then they are renamed to "app.log.2", "app.log.3" etc.
respectively. If maxBytes is zero, rollover never occurs.
"""
# If rotation/rollover is wanted, it doesn't make sense to use another
# mode. If for example 'w' were specified, then if there were multiple
# runs of the calling application, the logs from previous runs would be
# lost if the 'w' is respected, because the log file would be truncated
# on each run.
if maxBytes > 0:
mode = 'a'
BaseRotatingHandler.__init__(self, filename, mode, encoding, delay)
self.maxBytes = maxBytes
self.backupCount = backupCount def doRollover(self):
"""
Do a rollover, as described in __init__().
"""
if self.stream:
self.stream.close()
self.stream = None
if self.backupCount > 0:
for i in range(self.backupCount - 1, 0, -1):
sfn = self.rotation_filename("%s.%d" % (self.baseFilename, i))
dfn = self.rotation_filename("%s.%d" % (self.baseFilename,
i + 1))
if os.path.exists(sfn):
if os.path.exists(dfn):
os.remove(dfn)
os.rename(sfn, dfn)
dfn = self.rotation_filename(self.baseFilename + ".1")
if os.path.exists(dfn):
os.remove(dfn)
self.rotate(self.baseFilename, dfn)
if not self.delay:
self.stream = self._open() def shouldRollover(self, record):
"""
Determine if rollover should occur. Basically, see if the supplied record would cause the file to exceed
the size limit we have.
"""
if self.stream is None: # delay was set...
self.stream = self._open()
if self.maxBytes > 0: # are we rolling over?
msg = "%s\n" % self.format(record)
self.stream.seek(0, 2) #due to non-posix-compliant Windows feature
if self.stream.tell() + len(msg) >= self.maxBytes:
return 1
return 0 class TimedRotatingFileHandler(BaseRotatingHandler):
"""
Handler for logging to a file, rotating the log file at certain timed
intervals. If backupCount is > 0, when rollover is done, no more than backupCount
files are kept - the oldest ones are deleted.
"""
def __init__(self, filename, when='h', interval=1, backupCount=0, encoding=None, delay=False, utc=False, atTime=None):
BaseRotatingHandler.__init__(self, filename, 'a', encoding, delay)
self.when = when.upper()
self.backupCount = backupCount
self.utc = utc
self.atTime = atTime
# Calculate the real rollover interval, which is just the number of
# seconds between rollovers. Also set the filename suffix used when
# a rollover occurs. Current 'when' events supported:
# S - Seconds
# M - Minutes
# H - Hours
# D - Days
# midnight - roll over at midnight
# W{0-6} - roll over on a certain day; 0 - Monday
#
# Case of the 'when' specifier is not important; lower or upper case
# will work.
if self.when == 'S':
self.interval = 1 # one second
self.suffix = "%Y-%m-%d_%H-%M-%S"
self.extMatch = r"^\d{4}-\d{2}-\d{2}_\d{2}-\d{2}-\d{2}(\.\w+)?$"
elif self.when == 'M':
self.interval = 60 # one minute
self.suffix = "%Y-%m-%d_%H-%M"
self.extMatch = r"^\d{4}-\d{2}-\d{2}_\d{2}-\d{2}(\.\w+)?$"
elif self.when == 'H':
self.interval = 60 * 60 # one hour
self.suffix = "%Y-%m-%d_%H"
self.extMatch = r"^\d{4}-\d{2}-\d{2}_\d{2}(\.\w+)?$"
elif self.when == 'D' or self.when == 'MIDNIGHT':
self.interval = 60 * 60 * 24 # one day
self.suffix = "%Y-%m-%d"
self.extMatch = r"^\d{4}-\d{2}-\d{2}(\.\w+)?$"
elif self.when.startswith('W'):
self.interval = 60 * 60 * 24 * 7 # one week
if len(self.when) != 2:
raise ValueError("You must specify a day for weekly rollover from 0 to 6 (0 is Monday): %s" % self.when)
if self.when[1] < '' or self.when[1] > '':
raise ValueError("Invalid day specified for weekly rollover: %s" % self.when)
self.dayOfWeek = int(self.when[1])
self.suffix = "%Y-%m-%d"
self.extMatch = r"^\d{4}-\d{2}-\d{2}(\.\w+)?$"
else:
raise ValueError("Invalid rollover interval specified: %s" % self.when) self.extMatch = re.compile(self.extMatch, re.ASCII)
self.interval = self.interval * interval # multiply by units requested
# The following line added because the filename passed in could be a
# path object (see Issue #27493), but self.baseFilename will be a string
filename = self.baseFilename
if os.path.exists(filename):
t = os.stat(filename)[ST_MTIME]
else:
t = int(time.time())
self.rolloverAt = self.computeRollover(t) def computeRollover(self, currentTime):
"""
Work out the rollover time based on the specified time.
"""
result = currentTime + self.interval
# If we are rolling over at midnight or weekly, then the interval is already known.
# What we need to figure out is WHEN the next interval is. In other words,
# if you are rolling over at midnight, then your base interval is 1 day,
# but you want to start that one day clock at midnight, not now. So, we
# have to fudge the rolloverAt value in order to trigger the first rollover
# at the right time. After that, the regular interval will take care of
# the rest. Note that this code doesn't care about leap seconds. :)
if self.when == 'MIDNIGHT' or self.when.startswith('W'):
# This could be done with less code, but I wanted it to be clear
if self.utc:
t = time.gmtime(currentTime)
else:
t = time.localtime(currentTime)
currentHour = t[3]
currentMinute = t[4]
currentSecond = t[5]
currentDay = t[6]
# r is the number of seconds left between now and the next rotation
if self.atTime is None:
rotate_ts = _MIDNIGHT
else:
rotate_ts = ((self.atTime.hour * 60 + self.atTime.minute)*60 +
self.atTime.second) r = rotate_ts - ((currentHour * 60 + currentMinute) * 60 +
currentSecond)
if r < 0:
# Rotate time is before the current time (for example when
# self.rotateAt is 13:45 and it now 14:15), rotation is
# tomorrow.
r += _MIDNIGHT
currentDay = (currentDay + 1) % 7
result = currentTime + r
# If we are rolling over on a certain day, add in the number of days until
# the next rollover, but offset by 1 since we just calculated the time
# until the next day starts. There are three cases:
# Case 1) The day to rollover is today; in this case, do nothing
# Case 2) The day to rollover is further in the interval (i.e., today is
# day 2 (Wednesday) and rollover is on day 6 (Sunday). Days to
# next rollover is simply 6 - 2 - 1, or 3.
# Case 3) The day to rollover is behind us in the interval (i.e., today
# is day 5 (Saturday) and rollover is on day 3 (Thursday).
# Days to rollover is 6 - 5 + 3, or 4. In this case, it's the
# number of days left in the current week (1) plus the number
# of days in the next week until the rollover day (3).
# The calculations described in 2) and 3) above need to have a day added.
# This is because the above time calculation takes us to midnight on this
# day, i.e. the start of the next day.
if self.when.startswith('W'):
day = currentDay # 0 is Monday
if day != self.dayOfWeek:
if day < self.dayOfWeek:
daysToWait = self.dayOfWeek - day
else:
daysToWait = 6 - day + self.dayOfWeek + 1
newRolloverAt = result + (daysToWait * (60 * 60 * 24))
if not self.utc:
dstNow = t[-1]
dstAtRollover = time.localtime(newRolloverAt)[-1]
if dstNow != dstAtRollover:
if not dstNow: # DST kicks in before next rollover, so we need to deduct an hour
addend = -3600
else: # DST bows out before next rollover, so we need to add an hour
addend = 3600
newRolloverAt += addend
result = newRolloverAt
return result def shouldRollover(self, record):
"""
Determine if rollover should occur. record is not used, as we are just comparing times, but it is needed so
the method signatures are the same
"""
t = int(time.time())
if t >= self.rolloverAt:
return 1
return 0 def getFilesToDelete(self):
"""
Determine the files to delete when rolling over. More specific than the earlier method, which just used glob.glob().
"""
dirName, baseName = os.path.split(self.baseFilename)
fileNames = os.listdir(dirName)
result = []
prefix = baseName + "."
plen = len(prefix)
for fileName in fileNames:
if fileName[:plen] == prefix:
suffix = fileName[plen:]
if self.extMatch.match(suffix):
result.append(os.path.join(dirName, fileName))
if len(result) < self.backupCount:
result = []
else:
result.sort()
result = result[:len(result) - self.backupCount]
return result def doRollover(self):
"""
do a rollover; in this case, a date/time stamp is appended to the filename
when the rollover happens. However, you want the file to be named for the
start of the interval, not the current time. If there is a backup count,
then we have to get a list of matching filenames, sort them and remove
the one with the oldest suffix.
"""
if self.stream:
self.stream.close()
self.stream = None
# get the time that this sequence started at and make it a TimeTuple
currentTime = int(time.time())
dstNow = time.localtime(currentTime)[-1]
t = self.rolloverAt - self.interval
if self.utc:
timeTuple = time.gmtime(t)
else:
timeTuple = time.localtime(t)
dstThen = timeTuple[-1]
if dstNow != dstThen:
if dstNow:
addend = 3600
else:
addend = -3600
timeTuple = time.localtime(t + addend)
dfn = self.rotation_filename(self.baseFilename + "." +
time.strftime(self.suffix, timeTuple))
if os.path.exists(dfn):
os.remove(dfn)
self.rotate(self.baseFilename, dfn)
if self.backupCount > 0:
for s in self.getFilesToDelete():
os.remove(s)
if not self.delay:
self.stream = self._open()
newRolloverAt = self.computeRollover(currentTime)
while newRolloverAt <= currentTime:
newRolloverAt = newRolloverAt + self.interval
#If DST changes and midnight or weekly rollover, adjust for this.
if (self.when == 'MIDNIGHT' or self.when.startswith('W')) and not self.utc:
dstAtRollover = time.localtime(newRolloverAt)[-1]
if dstNow != dstAtRollover:
if not dstNow: # DST kicks in before next rollover, so we need to deduct an hour
addend = -3600
else: # DST bows out before next rollover, so we need to add an hour
addend = 3600
newRolloverAt += addend
self.rolloverAt = newRolloverAt class WatchedFileHandler(logging.FileHandler):
"""
A handler for logging to a file, which watches the file
to see if it has changed while in use. This can happen because of
usage of programs such as newsyslog and logrotate which perform
log file rotation. This handler, intended for use under Unix,
watches the file to see if it has changed since the last emit.
(A file has changed if its device or inode have changed.)
If it has changed, the old file stream is closed, and the file
opened to get a new stream. This handler is not appropriate for use under Windows, because
under Windows open files cannot be moved or renamed - logging
opens the files with exclusive locks - and so there is no need
for such a handler. Furthermore, ST_INO is not supported under
Windows; stat always returns zero for this value. This handler is based on a suggestion and patch by Chad J.
Schroeder.
"""
def __init__(self, filename, mode='a', encoding=None, delay=False):
logging.FileHandler.__init__(self, filename, mode, encoding, delay)
self.dev, self.ino = -1, -1
self._statstream() def _statstream(self):
if self.stream:
sres = os.fstat(self.stream.fileno())
self.dev, self.ino = sres[ST_DEV], sres[ST_INO] def reopenIfNeeded(self):
"""
Reopen log file if needed. Checks if the underlying file has changed, and if it
has, close the old stream and reopen the file to get the
current stream.
"""
# Reduce the chance of race conditions by stat'ing by path only
# once and then fstat'ing our new fd if we opened a new log stream.
# See issue #14632: Thanks to John Mulligan for the problem report
# and patch.
try:
# stat the file by path, checking for existence
sres = os.stat(self.baseFilename)
except FileNotFoundError:
sres = None
# compare file system stat with that of our stream file handle
if not sres or sres[ST_DEV] != self.dev or sres[ST_INO] != self.ino:
if self.stream is not None:
# we have an open file handle, clean it up
self.stream.flush()
self.stream.close()
self.stream = None # See Issue #21742: _open () might fail.
# open a new file handle and get new stat info from that fd
self.stream = self._open()
self._statstream() def emit(self, record):
"""
Emit a record. If underlying file has changed, reopen the file before emitting the
record to it.
"""
self.reopenIfNeeded()
logging.FileHandler.emit(self, record) class SocketHandler(logging.Handler):
"""
A handler class which writes logging records, in pickle format, to
a streaming socket. The socket is kept open across logging calls.
If the peer resets it, an attempt is made to reconnect on the next call.
The pickle which is sent is that of the LogRecord's attribute dictionary
(__dict__), so that the receiver does not need to have the logging module
installed in order to process the logging event. To unpickle the record at the receiving end into a LogRecord, use the
makeLogRecord function.
""" def __init__(self, host, port):
"""
Initializes the handler with a specific host address and port. When the attribute *closeOnError* is set to True - if a socket error
occurs, the socket is silently closed and then reopened on the next
logging call.
"""
logging.Handler.__init__(self)
self.host = host
self.port = port
if port is None:
self.address = host
else:
self.address = (host, port)
self.sock = None
self.closeOnError = False
self.retryTime = None
#
# Exponential backoff parameters.
#
self.retryStart = 1.0
self.retryMax = 30.0
self.retryFactor = 2.0 def makeSocket(self, timeout=1):
"""
A factory method which allows subclasses to define the precise
type of socket they want.
"""
if self.port is not None:
result = socket.create_connection(self.address, timeout=timeout)
else:
result = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
result.settimeout(timeout)
try:
result.connect(self.address)
except OSError:
result.close() # Issue 19182
raise
return result def createSocket(self):
"""
Try to create a socket, using an exponential backoff with
a max retry time. Thanks to Robert Olson for the original patch
(SF #815911) which has been slightly refactored.
"""
now = time.time()
# Either retryTime is None, in which case this
# is the first time back after a disconnect, or
# we've waited long enough.
if self.retryTime is None:
attempt = True
else:
attempt = (now >= self.retryTime)
if attempt:
try:
self.sock = self.makeSocket()
self.retryTime = None # next time, no delay before trying
except OSError:
#Creation failed, so set the retry time and return.
if self.retryTime is None:
self.retryPeriod = self.retryStart
else:
self.retryPeriod = self.retryPeriod * self.retryFactor
if self.retryPeriod > self.retryMax:
self.retryPeriod = self.retryMax
self.retryTime = now + self.retryPeriod def send(self, s):
"""
Send a pickled string to the socket. This function allows for partial sends which can happen when the
network is busy.
"""
if self.sock is None:
self.createSocket()
#self.sock can be None either because we haven't reached the retry
#time yet, or because we have reached the retry time and retried,
#but are still unable to connect.
if self.sock:
try:
self.sock.sendall(s)
except OSError: #pragma: no cover
self.sock.close()
self.sock = None # so we can call createSocket next time def makePickle(self, record):
"""
Pickles the record in binary format with a length prefix, and
returns it ready for transmission across the socket.
"""
ei = record.exc_info
if ei:
# just to get traceback text into record.exc_text ...
dummy = self.format(record)
# See issue #14436: If msg or args are objects, they may not be
# available on the receiving end. So we convert the msg % args
# to a string, save it as msg and zap the args.
d = dict(record.__dict__)
d['msg'] = record.getMessage()
d['args'] = None
d['exc_info'] = None
# Issue #25685: delete 'message' if present: redundant with 'msg'
d.pop('message', None)
s = pickle.dumps(d, 1)
slen = struct.pack(">L", len(s))
return slen + s def handleError(self, record):
"""
Handle an error during logging. An error has occurred during logging. Most likely cause -
connection lost. Close the socket so that we can retry on the
next event.
"""
if self.closeOnError and self.sock:
self.sock.close()
self.sock = None #try to reconnect next time
else:
logging.Handler.handleError(self, record) def emit(self, record):
"""
Emit a record. Pickles the record and writes it to the socket in binary format.
If there is an error with the socket, silently drop the packet.
If there was a problem with the socket, re-establishes the
socket.
"""
try:
s = self.makePickle(record)
self.send(s)
except Exception:
self.handleError(record) def close(self):
"""
Closes the socket.
"""
self.acquire()
try:
sock = self.sock
if sock:
self.sock = None
sock.close()
logging.Handler.close(self)
finally:
self.release() class DatagramHandler(SocketHandler):
"""
A handler class which writes logging records, in pickle format, to
a datagram socket. The pickle which is sent is that of the LogRecord's
attribute dictionary (__dict__), so that the receiver does not need to
have the logging module installed in order to process the logging event. To unpickle the record at the receiving end into a LogRecord, use the
makeLogRecord function. """
def __init__(self, host, port):
"""
Initializes the handler with a specific host address and port.
"""
SocketHandler.__init__(self, host, port)
self.closeOnError = False def makeSocket(self):
"""
The factory method of SocketHandler is here overridden to create
a UDP socket (SOCK_DGRAM).
"""
if self.port is None:
family = socket.AF_UNIX
else:
family = socket.AF_INET
s = socket.socket(family, socket.SOCK_DGRAM)
return s def send(self, s):
"""
Send a pickled string to a socket. This function no longer allows for partial sends which can happen
when the network is busy - UDP does not guarantee delivery and
can deliver packets out of sequence.
"""
if self.sock is None:
self.createSocket()
self.sock.sendto(s, self.address) class SysLogHandler(logging.Handler):
"""
A handler class which sends formatted logging records to a syslog
server. Based on Sam Rushing's syslog module:
http://www.nightmare.com/squirl/python-ext/misc/syslog.py
Contributed by Nicolas Untz (after which minor refactoring changes
have been made).
""" # from <linux/sys/syslog.h>:
# ======================================================================
# priorities/facilities are encoded into a single 32-bit quantity, where
# the bottom 3 bits are the priority (0-7) and the top 28 bits are the
# facility (0-big number). Both the priorities and the facilities map
# roughly one-to-one to strings in the syslogd(8) source code. This
# mapping is included in this file.
#
# priorities (these are ordered) LOG_EMERG = 0 # system is unusable
LOG_ALERT = 1 # action must be taken immediately
LOG_CRIT = 2 # critical conditions
LOG_ERR = 3 # error conditions
LOG_WARNING = 4 # warning conditions
LOG_NOTICE = 5 # normal but significant condition
LOG_INFO = 6 # informational
LOG_DEBUG = 7 # debug-level messages # facility codes
LOG_KERN = 0 # kernel messages
LOG_USER = 1 # random user-level messages
LOG_MAIL = 2 # mail system
LOG_DAEMON = 3 # system daemons
LOG_AUTH = 4 # security/authorization messages
LOG_SYSLOG = 5 # messages generated internally by syslogd
LOG_LPR = 6 # line printer subsystem
LOG_NEWS = 7 # network news subsystem
LOG_UUCP = 8 # UUCP subsystem
LOG_CRON = 9 # clock daemon
LOG_AUTHPRIV = 10 # security/authorization messages (private)
LOG_FTP = 11 # FTP daemon # other codes through 15 reserved for system use
LOG_LOCAL0 = 16 # reserved for local use
LOG_LOCAL1 = 17 # reserved for local use
LOG_LOCAL2 = 18 # reserved for local use
LOG_LOCAL3 = 19 # reserved for local use
LOG_LOCAL4 = 20 # reserved for local use
LOG_LOCAL5 = 21 # reserved for local use
LOG_LOCAL6 = 22 # reserved for local use
LOG_LOCAL7 = 23 # reserved for local use priority_names = {
"alert": LOG_ALERT,
"crit": LOG_CRIT,
"critical": LOG_CRIT,
"debug": LOG_DEBUG,
"emerg": LOG_EMERG,
"err": LOG_ERR,
"error": LOG_ERR, # DEPRECATED
"info": LOG_INFO,
"notice": LOG_NOTICE,
"panic": LOG_EMERG, # DEPRECATED
"warn": LOG_WARNING, # DEPRECATED
"warning": LOG_WARNING,
} facility_names = {
"auth": LOG_AUTH,
"authpriv": LOG_AUTHPRIV,
"cron": LOG_CRON,
"daemon": LOG_DAEMON,
"ftp": LOG_FTP,
"kern": LOG_KERN,
"lpr": LOG_LPR,
"mail": LOG_MAIL,
"news": LOG_NEWS,
"security": LOG_AUTH, # DEPRECATED
"syslog": LOG_SYSLOG,
"user": LOG_USER,
"uucp": LOG_UUCP,
"local0": LOG_LOCAL0,
"local1": LOG_LOCAL1,
"local2": LOG_LOCAL2,
"local3": LOG_LOCAL3,
"local4": LOG_LOCAL4,
"local5": LOG_LOCAL5,
"local6": LOG_LOCAL6,
"local7": LOG_LOCAL7,
} #The map below appears to be trivially lowercasing the key. However,
#there's more to it than meets the eye - in some locales, lowercasing
#gives unexpected results. See SF #1524081: in the Turkish locale,
#"INFO".lower() != "info"
priority_map = {
"DEBUG" : "debug",
"INFO" : "info",
"WARNING" : "warning",
"ERROR" : "error",
"CRITICAL" : "critical"
} def __init__(self, address=('localhost', SYSLOG_UDP_PORT),
facility=LOG_USER, socktype=None):
"""
Initialize a handler. If address is specified as a string, a UNIX socket is used. To log to a
local syslogd, "SysLogHandler(address="/dev/log")" can be used.
If facility is not specified, LOG_USER is used. If socktype is
specified as socket.SOCK_DGRAM or socket.SOCK_STREAM, that specific
socket type will be used. For Unix sockets, you can also specify a
socktype of None, in which case socket.SOCK_DGRAM will be used, falling
back to socket.SOCK_STREAM.
"""
logging.Handler.__init__(self) self.address = address
self.facility = facility
self.socktype = socktype if isinstance(address, str):
self.unixsocket = True
# Syslog server may be unavailable during handler initialisation.
# C's openlog() function also ignores connection errors.
# Moreover, we ignore these errors while logging, so it not worse
# to ignore it also here.
try:
self._connect_unixsocket(address)
except OSError:
pass
else:
self.unixsocket = False
if socktype is None:
socktype = socket.SOCK_DGRAM
host, port = address
ress = socket.getaddrinfo(host, port, 0, socktype)
if not ress:
raise OSError("getaddrinfo returns an empty list")
for res in ress:
af, socktype, proto, _, sa = res
err = sock = None
try:
sock = socket.socket(af, socktype, proto)
if socktype == socket.SOCK_STREAM:
sock.connect(sa)
break
except OSError as exc:
err = exc
if sock is not None:
sock.close()
if err is not None:
raise err
self.socket = sock
self.socktype = socktype def _connect_unixsocket(self, address):
use_socktype = self.socktype
if use_socktype is None:
use_socktype = socket.SOCK_DGRAM
self.socket = socket.socket(socket.AF_UNIX, use_socktype)
try:
self.socket.connect(address)
# it worked, so set self.socktype to the used type
self.socktype = use_socktype
except OSError:
self.socket.close()
if self.socktype is not None:
# user didn't specify falling back, so fail
raise
use_socktype = socket.SOCK_STREAM
self.socket = socket.socket(socket.AF_UNIX, use_socktype)
try:
self.socket.connect(address)
# it worked, so set self.socktype to the used type
self.socktype = use_socktype
except OSError:
self.socket.close()
raise def encodePriority(self, facility, priority):
"""
Encode the facility and priority. You can pass in strings or
integers - if strings are passed, the facility_names and
priority_names mapping dictionaries are used to convert them to
integers.
"""
if isinstance(facility, str):
facility = self.facility_names[facility]
if isinstance(priority, str):
priority = self.priority_names[priority]
return (facility << 3) | priority def close(self):
"""
Closes the socket.
"""
self.acquire()
try:
self.socket.close()
logging.Handler.close(self)
finally:
self.release() def mapPriority(self, levelName):
"""
Map a logging level name to a key in the priority_names map.
This is useful in two scenarios: when custom levels are being
used, and in the case where you can't do a straightforward
mapping by lowercasing the logging level name because of locale-
specific issues (see SF #1524081).
"""
return self.priority_map.get(levelName, "warning") ident = '' # prepended to all messages
append_nul = True # some old syslog daemons expect a NUL terminator def emit(self, record):
"""
Emit a record. The record is formatted, and then sent to the syslog server. If
exception information is present, it is NOT sent to the server.
"""
try:
msg = self.format(record)
if self.ident:
msg = self.ident + msg
if self.append_nul:
msg += '\000' # We need to convert record level to lowercase, maybe this will
# change in the future.
prio = '<%d>' % self.encodePriority(self.facility,
self.mapPriority(record.levelname))
prio = prio.encode('utf-8')
# Message is a string. Convert to bytes as required by RFC 5424
msg = msg.encode('utf-8')
msg = prio + msg
if self.unixsocket:
try:
self.socket.send(msg)
except OSError:
self.socket.close()
self._connect_unixsocket(self.address)
self.socket.send(msg)
elif self.socktype == socket.SOCK_DGRAM:
self.socket.sendto(msg, self.address)
else:
self.socket.sendall(msg)
except Exception:
self.handleError(record) class SMTPHandler(logging.Handler):
"""
A handler class which sends an SMTP email for each logging event.
"""
def __init__(self, mailhost, fromaddr, toaddrs, subject,
credentials=None, secure=None, timeout=5.0):
"""
Initialize the handler. Initialize the instance with the from and to addresses and subject
line of the email. To specify a non-standard SMTP port, use the
(host, port) tuple format for the mailhost argument. To specify
authentication credentials, supply a (username, password) tuple
for the credentials argument. To specify the use of a secure
protocol (TLS), pass in a tuple for the secure argument. This will
only be used when authentication credentials are supplied. The tuple
will be either an empty tuple, or a single-value tuple with the name
of a keyfile, or a 2-value tuple with the names of the keyfile and
certificate file. (This tuple is passed to the `starttls` method).
A timeout in seconds can be specified for the SMTP connection (the
default is one second).
"""
logging.Handler.__init__(self)
if isinstance(mailhost, (list, tuple)):
self.mailhost, self.mailport = mailhost
else:
self.mailhost, self.mailport = mailhost, None
if isinstance(credentials, (list, tuple)):
self.username, self.password = credentials
else:
self.username = None
self.fromaddr = fromaddr
if isinstance(toaddrs, str):
toaddrs = [toaddrs]
self.toaddrs = toaddrs
self.subject = subject
self.secure = secure
self.timeout = timeout def getSubject(self, record):
"""
Determine the subject for the email. If you want to specify a subject line which is record-dependent,
override this method.
"""
return self.subject def emit(self, record):
"""
Emit a record. Format the record and send it to the specified addressees.
"""
try:
import smtplib
from email.message import EmailMessage
import email.utils port = self.mailport
if not port:
port = smtplib.SMTP_PORT
smtp = smtplib.SMTP(self.mailhost, port, timeout=self.timeout)
msg = EmailMessage()
msg['From'] = self.fromaddr
msg['To'] = ','.join(self.toaddrs)
msg['Subject'] = self.getSubject(record)
msg['Date'] = email.utils.localtime()
msg.set_content(self.format(record))
if self.username:
if self.secure is not None:
smtp.ehlo()
smtp.starttls(*self.secure)
smtp.ehlo()
smtp.login(self.username, self.password)
smtp.send_message(msg)
smtp.quit()
except Exception:
self.handleError(record) class NTEventLogHandler(logging.Handler):
"""
A handler class which sends events to the NT Event Log. Adds a
registry entry for the specified application name. If no dllname is
provided, win32service.pyd (which contains some basic message
placeholders) is used. Note that use of these placeholders will make
your event logs big, as the entire message source is held in the log.
If you want slimmer logs, you have to pass in the name of your own DLL
which contains the message definitions you want to use in the event log.
"""
def __init__(self, appname, dllname=None, logtype="Application"):
logging.Handler.__init__(self)
try:
import win32evtlogutil, win32evtlog
self.appname = appname
self._welu = win32evtlogutil
if not dllname:
dllname = os.path.split(self._welu.__file__)
dllname = os.path.split(dllname[0])
dllname = os.path.join(dllname[0], r'win32service.pyd')
self.dllname = dllname
self.logtype = logtype
self._welu.AddSourceToRegistry(appname, dllname, logtype)
self.deftype = win32evtlog.EVENTLOG_ERROR_TYPE
self.typemap = {
logging.DEBUG : win32evtlog.EVENTLOG_INFORMATION_TYPE,
logging.INFO : win32evtlog.EVENTLOG_INFORMATION_TYPE,
logging.WARNING : win32evtlog.EVENTLOG_WARNING_TYPE,
logging.ERROR : win32evtlog.EVENTLOG_ERROR_TYPE,
logging.CRITICAL: win32evtlog.EVENTLOG_ERROR_TYPE,
}
except ImportError:
print("The Python Win32 extensions for NT (service, event "\
"logging) appear not to be available.")
self._welu = None def getMessageID(self, record):
"""
Return the message ID for the event record. If you are using your
own messages, you could do this by having the msg passed to the
logger being an ID rather than a formatting string. Then, in here,
you could use a dictionary lookup to get the message ID. This
version returns 1, which is the base message ID in win32service.pyd.
"""
return 1 def getEventCategory(self, record):
"""
Return the event category for the record. Override this if you want to specify your own categories. This version
returns 0.
"""
return 0 def getEventType(self, record):
"""
Return the event type for the record. Override this if you want to specify your own types. This version does
a mapping using the handler's typemap attribute, which is set up in
__init__() to a dictionary which contains mappings for DEBUG, INFO,
WARNING, ERROR and CRITICAL. If you are using your own levels you will
either need to override this method or place a suitable dictionary in
the handler's typemap attribute.
"""
return self.typemap.get(record.levelno, self.deftype) def emit(self, record):
"""
Emit a record. Determine the message ID, event category and event type. Then
log the message in the NT event log.
"""
if self._welu:
try:
id = self.getMessageID(record)
cat = self.getEventCategory(record)
type = self.getEventType(record)
msg = self.format(record)
self._welu.ReportEvent(self.appname, id, cat, type, [msg])
except Exception:
self.handleError(record) def close(self):
"""
Clean up this handler. You can remove the application name from the registry as a
source of event log entries. However, if you do this, you will
not be able to see the events as you intended in the Event Log
Viewer - it needs to be able to access the registry to get the
DLL name.
"""
#self._welu.RemoveSourceFromRegistry(self.appname, self.logtype)
logging.Handler.close(self) class HTTPHandler(logging.Handler):
"""
A class which sends records to a Web server, using either GET or
POST semantics.
"""
def __init__(self, host, url, method="GET", secure=False, credentials=None,
context=None):
"""
Initialize the instance with the host, the request URL, and the method
("GET" or "POST")
"""
logging.Handler.__init__(self)
method = method.upper()
if method not in ["GET", "POST"]:
raise ValueError("method must be GET or POST")
if not secure and context is not None:
raise ValueError("context parameter only makes sense "
"with secure=True")
self.host = host
self.url = url
self.method = method
self.secure = secure
self.credentials = credentials
self.context = context def mapLogRecord(self, record):
"""
Default implementation of mapping the log record into a dict
that is sent as the CGI data. Overwrite in your class.
Contributed by Franz Glasner.
"""
return record.__dict__ def emit(self, record):
"""
Emit a record. Send the record to the Web server as a percent-encoded dictionary
"""
try:
import http.client, urllib.parse
host = self.host
if self.secure:
h = http.client.HTTPSConnection(host, context=self.context)
else:
h = http.client.HTTPConnection(host)
url = self.url
data = urllib.parse.urlencode(self.mapLogRecord(record))
if self.method == "GET":
if (url.find('?') >= 0):
sep = '&'
else:
sep = '?'
url = url + "%c%s" % (sep, data)
h.putrequest(self.method, url)
# support multiple hosts on one IP address...
# need to strip optional :port from host, if present
i = host.find(":")
if i >= 0:
host = host[:i]
# See issue #30904: putrequest call above already adds this header
# on Python 3.x.
# h.putheader("Host", host)
if self.method == "POST":
h.putheader("Content-type",
"application/x-www-form-urlencoded")
h.putheader("Content-length", str(len(data)))
if self.credentials:
import base64
s = ('%s:%s' % self.credentials).encode('utf-8')
s = 'Basic ' + base64.b64encode(s).strip().decode('ascii')
h.putheader('Authorization', s)
h.endheaders()
if self.method == "POST":
h.send(data.encode('utf-8'))
h.getresponse() #can't do anything with the result
except Exception:
self.handleError(record) class BufferingHandler(logging.Handler):
"""
A handler class which buffers logging records in memory. Whenever each
record is added to the buffer, a check is made to see if the buffer should
be flushed. If it should, then flush() is expected to do what's needed.
"""
def __init__(self, capacity):
"""
Initialize the handler with the buffer size.
"""
logging.Handler.__init__(self)
self.capacity = capacity
self.buffer = [] def shouldFlush(self, record):
"""
Should the handler flush its buffer? Returns true if the buffer is up to capacity. This method can be
overridden to implement custom flushing strategies.
"""
return (len(self.buffer) >= self.capacity) def emit(self, record):
"""
Emit a record. Append the record. If shouldFlush() tells us to, call flush() to process
the buffer.
"""
self.buffer.append(record)
if self.shouldFlush(record):
self.flush() def flush(self):
"""
Override to implement custom flushing behaviour. This version just zaps the buffer to empty.
"""
self.acquire()
try:
self.buffer = []
finally:
self.release() def close(self):
"""
Close the handler. This version just flushes and chains to the parent class' close().
"""
try:
self.flush()
finally:
logging.Handler.close(self) class MemoryHandler(BufferingHandler):
"""
A handler class which buffers logging records in memory, periodically
flushing them to a target handler. Flushing occurs whenever the buffer
is full, or when an event of a certain severity or greater is seen.
"""
def __init__(self, capacity, flushLevel=logging.ERROR, target=None,
flushOnClose=True):
"""
Initialize the handler with the buffer size, the level at which
flushing should occur and an optional target. Note that without a target being set either here or via setTarget(),
a MemoryHandler is no use to anyone! The ``flushOnClose`` argument is ``True`` for backward compatibility
reasons - the old behaviour is that when the handler is closed, the
buffer is flushed, even if the flush level hasn't been exceeded nor the
capacity exceeded. To prevent this, set ``flushOnClose`` to ``False``.
"""
BufferingHandler.__init__(self, capacity)
self.flushLevel = flushLevel
self.target = target
# See Issue #26559 for why this has been added
self.flushOnClose = flushOnClose def shouldFlush(self, record):
"""
Check for buffer full or a record at the flushLevel or higher.
"""
return (len(self.buffer) >= self.capacity) or \
(record.levelno >= self.flushLevel) def setTarget(self, target):
"""
Set the target handler for this handler.
"""
self.target = target def flush(self):
"""
For a MemoryHandler, flushing means just sending the buffered
records to the target, if there is one. Override if you want
different behaviour. The record buffer is also cleared by this operation.
"""
self.acquire()
try:
if self.target:
for record in self.buffer:
self.target.handle(record)
self.buffer = []
finally:
self.release() def close(self):
"""
Flush, if appropriately configured, set the target to None and lose the
buffer.
"""
try:
if self.flushOnClose:
self.flush()
finally:
self.acquire()
try:
self.target = None
BufferingHandler.close(self)
finally:
self.release() class QueueHandler(logging.Handler):
"""
This handler sends events to a queue. Typically, it would be used together
with a multiprocessing Queue to centralise logging to file in one process
(in a multi-process application), so as to avoid file write contention
between processes. This code is new in Python 3.2, but this class can be copy pasted into
user code for use with earlier Python versions.
""" def __init__(self, queue):
"""
Initialise an instance, using the passed queue.
"""
logging.Handler.__init__(self)
self.queue = queue def enqueue(self, record):
"""
Enqueue a record. The base implementation uses put_nowait. You may want to override
this method if you want to use blocking, timeouts or custom queue
implementations.
"""
self.queue.put_nowait(record) def prepare(self, record):
"""
Prepares a record for queuing. The object returned by this method is
enqueued. The base implementation formats the record to merge the message
and arguments, and removes unpickleable items from the record
in-place. You might want to override this method if you want to convert
the record to a dict or JSON string, or send a modified copy
of the record while leaving the original intact.
"""
# The format operation gets traceback text into record.exc_text
# (if there's exception data), and also puts the message into
# record.message. We can then use this to replace the original
# msg + args, as these might be unpickleable. We also zap the
# exc_info attribute, as it's no longer needed and, if not None,
# will typically not be pickleable.
self.format(record)
record.msg = record.message
record.args = None
record.exc_info = None
return record def emit(self, record):
"""
Emit a record. Writes the LogRecord to the queue, preparing it for pickling first.
"""
try:
self.enqueue(self.prepare(record))
except Exception:
self.handleError(record) if threading:
class QueueListener(object):
"""
This class implements an internal threaded listener which watches for
LogRecords being added to a queue, removes them and passes them to a
list of handlers for processing.
"""
_sentinel = None def __init__(self, queue, *handlers, respect_handler_level=False):
"""
Initialise an instance with the specified queue and
handlers.
"""
self.queue = queue
self.handlers = handlers
self._thread = None
self.respect_handler_level = respect_handler_level def dequeue(self, block):
"""
Dequeue a record and return it, optionally blocking. The base implementation uses get. You may want to override this method
if you want to use timeouts or work with custom queue implementations.
"""
return self.queue.get(block) def start(self):
"""
Start the listener. This starts up a background thread to monitor the queue for
LogRecords to process.
"""
self._thread = t = threading.Thread(target=self._monitor)
t.daemon = True
t.start() def prepare(self , record):
"""
Prepare a record for handling. This method just returns the passed-in record. You may want to
override this method if you need to do any custom marshalling or
manipulation of the record before passing it to the handlers.
"""
return record def handle(self, record):
"""
Handle a record. This just loops through the handlers offering them the record
to handle.
"""
record = self.prepare(record)
for handler in self.handlers:
if not self.respect_handler_level:
process = True
else:
process = record.levelno >= handler.level
if process:
handler.handle(record) def _monitor(self):
"""
Monitor the queue for records, and ask the handler
to deal with them. This method runs on a separate, internal thread.
The thread will terminate if it sees a sentinel object in the queue.
"""
q = self.queue
has_task_done = hasattr(q, 'task_done')
while True:
try:
record = self.dequeue(True)
if record is self._sentinel:
break
self.handle(record)
if has_task_done:
q.task_done()
except queue.Empty:
break def enqueue_sentinel(self):
"""
This is used to enqueue the sentinel record. The base implementation uses put_nowait. You may want to override this
method if you want to use timeouts or work with custom queue
implementations.
"""
self.queue.put_nowait(self._sentinel) def stop(self):
"""
Stop the listener. This asks the thread to terminate, and then waits for it to do so.
Note that if you don't call this before your application exits, there
may be some records still left on the queue, which won't be processed.
"""
self.enqueue_sentinel()
self._thread.join()
self._thread = None
handlers.py