一、作用域
对于变量的作用域,执行声明并在内存中存在,该变量就可以在下面的代码中使用。
二、三元运算
result = 值1 if 条件 else 值2
如果条件为真:result = 值1
如果条件为假:result = 值2
例如:
result = 'dengyu' if == else 'budengyu'
print (result)
dengyu
三、进制
- 二进制,01
- 八进制,01234567
- 十进制,0123456789
- 十六进制,0123456789ABCDEF
Python基础 |
所以,以下这些值都是对象: "wupeiqi"、38、['北京', '上海', '深圳'],并且是根据不同的类生成的对象
1、整数类型源码解析以及实例 #长整型与整数基本类似
class int(object):
"""
int(x=0) -> int or long(将字符串整数转换为整数或者长整数,3.0不区分)
int(x, base=10) -> int or long(将任意类型的进制按照指定的进制转换为10禁制
)
print (int('f',base=16))
>>>15
>>> int('0b100', base=0)
"""
def bit_length(self):
""" 返回表示该数字的时占用的最少位数,二进制的位数 """
num = 15
print (num.bit_length())
>>> 4 # # 8 4 2 1 0000 1111 占4位
>>> abs(-19)
"""
int.bit_length() -> int Number of bits necessary to represent self in binary.
>>> bin(37)
'0b100101'
>>> (37).bit_length()
"""
return 0 def conjugate(self, *args, **kwargs): # real signature unknown
""" 返回该复数的共轭复数 """
""" Returns self, the complex conjugate of any int. """
pass def __abs__(self):
""" 返回绝对值 """
""" x.__abs__() <==> abs(x) """
pass def __add__(self, y):
""" x.__add__(y) <==> x+y """
pass def __and__(self, y):
""" x.__and__(y) <==> x&y """
pass def __cmp__(self, y):
""" 比较两个数大小 """
""" x.__cmp__(y) <==> cmp(x,y) """
pass def __coerce__(self, y):
""" 强制生成一个元组 """
""" x.__coerce__(y) <==> coerce(x, y) """
pass def __divmod__(self, y):
""" 相除,得到商和余数组成的元组 """
""" x.__divmod__(y) <==> divmod(x, y) """
pass def __div__(self, y):
""" x.__div__(y) <==> x/y """
pass def __float__(self):
""" 转换为浮点类型 """
""" x.__float__() <==> float(x) """
pass def __floordiv__(self, y):
""" x.__floordiv__(y) <==> x//y """
pass def __format__(self, *args, **kwargs): # real signature unknown
pass def __getattribute__(self, name):
""" x.__getattribute__('name') <==> x.name """
pass def __getnewargs__(self, *args, **kwargs): # real signature unknown
""" 内部调用 __new__方法或创建对象时传入参数使用 """
pass def __hash__(self):
"""如果对象object为哈希表类型,返回对象object的哈希值。哈希值为整数。在字典查找中,哈希值用于快速比较字典的键。两个数值如果相等,则哈希值也相等。"""
""" x.__hash__() <==> hash(x) """
pass def __hex__(self):
""" 返回当前数的 十六进制 表示 """
""" x.__hex__() <==> hex(x) """
pass def __index__(self):
""" 用于切片,数字无意义 """
""" x[y:z] <==> x[y.__index__():z.__index__()] """
pass def __init__(self, x, base=10): # known special case of int.__init__
""" 构造方法,执行 x = 123 或 x = int(10) 时,自动调用,暂时忽略 """
"""
int(x=0) -> int or long
int(x, base=10) -> int or long Convert a number or string to an integer, or return 0 if no arguments
are given. If x is floating point, the conversion truncates towards zero.
If x is outside the integer range, the function returns a long instead. If x is not a number or if base is given, then x must be a string or
Unicode object representing an integer literal in the given base. The
literal can be preceded by '+' or '-' and be surrounded by whitespace.
The base defaults to 10. Valid bases are 0 and 2-36. Base 0 means to
interpret the base from the string as an integer literal.
>>> int('0b100', base=0)
# (copied from class doc)
"""
pass def __int__(self):
""" 转换为整数 """
""" x.__int__() <==> int(x) """
pass def __invert__(self):
""" x.__invert__() <==> ~x """
pass def __long__(self):
""" 转换为长整数 """
""" x.__long__() <==> long(x) """
pass def __lshift__(self, y):
""" x.__lshift__(y) <==> x<<y """
pass def __mod__(self, y):
""" x.__mod__(y) <==> x%y """
pass def __mul__(self, y):
""" x.__mul__(y) <==> x*y """
pass def __neg__(self):
""" x.__neg__() <==> -x """
pass @staticmethod # known case of __new__
def __new__(S, *more):
""" T.__new__(S, ...) -> a new object with type S, a subtype of T """
pass def __nonzero__(self):
""" x.__nonzero__() <==> x != 0 """
pass def __oct__(self):
""" 返回改值的 八进制 表示 """
""" x.__oct__() <==> oct(x) """
pass def __or__(self, y):
""" x.__or__(y) <==> x|y """
pass def __pos__(self):
""" x.__pos__() <==> +x """
pass def __pow__(self, y, z=None):
""" 幂,次方 """
""" x.__pow__(y[, z]) <==> pow(x, y[, z]) """
pass def __radd__(self, y):
""" x.__radd__(y) <==> y+x """
pass def __rand__(self, y):
""" x.__rand__(y) <==> y&x """
pass def __rdivmod__(self, y):
""" x.__rdivmod__(y) <==> divmod(y, x) """
pass def __rdiv__(self, y):
""" x.__rdiv__(y) <==> y/x """
pass def __repr__(self):
"""转化为解释器可读取的形式 """
""" x.__repr__() <==> repr(x) """
pass def __str__(self):
"""转换为人阅读的形式,如果没有适于人阅读的解释形式的话,则返回解释器课阅读的形式"""
""" x.__str__() <==> str(x) """
pass def __rfloordiv__(self, y):
""" x.__rfloordiv__(y) <==> y//x """
pass def __rlshift__(self, y):
""" x.__rlshift__(y) <==> y<<x """
pass def __rmod__(self, y):
""" x.__rmod__(y) <==> y%x """
pass def __rmul__(self, y):
""" x.__rmul__(y) <==> y*x """
pass def __ror__(self, y):
""" x.__ror__(y) <==> y|x """
pass def __rpow__(self, x, z=None):
""" y.__rpow__(x[, z]) <==> pow(x, y[, z]) """
pass def __rrshift__(self, y):
""" x.__rrshift__(y) <==> y>>x """
pass def __rshift__(self, y):
""" x.__rshift__(y) <==> x>>y """
pass def __rsub__(self, y):
""" x.__rsub__(y) <==> y-x """
pass def __rtruediv__(self, y):
""" x.__rtruediv__(y) <==> y/x """
pass def __rxor__(self, y):
""" x.__rxor__(y) <==> y^x """
pass def __sub__(self, y):
""" x.__sub__(y) <==> x-y """
pass def __truediv__(self, y):
""" x.__truediv__(y) <==> x/y """
pass def __trunc__(self, *args, **kwargs):
""" 返回数值被截取为整形的值,在整形中无意义 """
pass def __xor__(self, y):
""" x.__xor__(y) <==> x^y """
pass denominator = property(lambda self: object(), lambda self, v: None, lambda self: None) # default
""" 分母 = 1 """
"""the denominator of a rational number in lowest terms""" imag = property(lambda self: object(), lambda self, v: None, lambda self: None) # default
""" 虚数,无意义 """
"""the imaginary part of a complex number""" numerator = property(lambda self: object(), lambda self, v: None, lambda self: None) # default
""" 分子 = 数字大小 """
"""the numerator of a rational number in lowest terms""" real = property(lambda self: object(), lambda self, v: None, lambda self: None) # default
""" 实属,无意义 """
"""the real part of a complex number"""
四.浮点型
class float(object):
"""
float(x) -> floating point number Convert a string or number to a floating point number, if possible.
"""
def as_integer_ratio(self):
""" 获取改值的最简比 """
"""
float.as_integer_ratio() -> (int, int) Return a pair of integers, whose ratio is exactly equal to the original
float and with a positive denominator.
Raise OverflowError on infinities and a ValueError on NaNs. >>> (10.0).as_integer_ratio()
(10, 1)
>>> (0.0).as_integer_ratio()
(0, 1)
>>> (-.25).as_integer_ratio()
(-1, 4)
"""
pass def conjugate(self, *args, **kwargs): # real signature unknown
""" Return self, the complex conjugate of any float. """
pass def fromhex(self, string):
""" 将十六进制字符串转换成浮点型 """
"""
float.fromhex(string) -> float Create a floating-point number from a hexadecimal string.
>>> float.fromhex('0x1.ffffp10')
2047.984375
>>> float.fromhex('-0x1p-1074')
-4.9406564584124654e-324
"""
return 0.0 def hex(self):
""" 返回当前值的 16 进制表示 """
"""
float.hex() -> string Return a hexadecimal representation of a floating-point number.
>>> (-0.1).hex()
'-0x1.999999999999ap-4'
>>> 3.14159.hex()
'0x1.921f9f01b866ep+1'
"""
return "" def is_integer(self, *args, **kwargs): # real signature unknown
""" Return True if the float is an integer. """
pass def __abs__(self):
""" x.__abs__() <==> abs(x) """
pass def __add__(self, y):
""" x.__add__(y) <==> x+y """
pass def __coerce__(self, y):
""" x.__coerce__(y) <==> coerce(x, y) """
pass def __divmod__(self, y):
""" x.__divmod__(y) <==> divmod(x, y) """
pass def __div__(self, y):
""" x.__div__(y) <==> x/y """
pass def __eq__(self, y):
""" x.__eq__(y) <==> x==y """
pass def __float__(self):
""" x.__float__() <==> float(x) """
pass def __floordiv__(self, y):
""" x.__floordiv__(y) <==> x//y """
pass def __format__(self, format_spec):
"""
float.__format__(format_spec) -> string Formats the float according to format_spec.
"""
return "" def __getattribute__(self, name):
""" x.__getattribute__('name') <==> x.name """
pass def __getformat__(self, typestr):
"""
float.__getformat__(typestr) -> string You probably don't want to use this function. It exists mainly to be
used in Python's test suite. typestr must be 'double' or 'float'. This function returns whichever of
'unknown', 'IEEE, big-endian' or 'IEEE, little-endian' best describes the
format of floating point numbers used by the C type named by typestr.
"""
return "" def __getnewargs__(self, *args, **kwargs): # real signature unknown
pass def __ge__(self, y):
""" x.__ge__(y) <==> x>=y """
pass def __gt__(self, y):
""" x.__gt__(y) <==> x>y """
pass def __hash__(self):
""" x.__hash__() <==> hash(x) """
pass def __init__(self, x):
pass def __int__(self):
""" x.__int__() <==> int(x) """
pass def __le__(self, y):
""" x.__le__(y) <==> x<=y """
pass def __long__(self):
""" x.__long__() <==> long(x) """
pass def __lt__(self, y):
""" x.__lt__(y) <==> x<y """
pass def __mod__(self, y):
""" x.__mod__(y) <==> x%y """
pass def __mul__(self, y):
""" x.__mul__(y) <==> x*y """
pass def __neg__(self):
""" x.__neg__() <==> -x """
pass @staticmethod # known case of __new__
def __new__(S, *more):
""" T.__new__(S, ...) -> a new object with type S, a subtype of T """
pass def __ne__(self, y):
""" x.__ne__(y) <==> x!=y """
pass def __nonzero__(self):
""" x.__nonzero__() <==> x != 0 """
pass def __pos__(self):
""" x.__pos__() <==> +x """
pass def __pow__(self, y, z=None):
""" x.__pow__(y[, z]) <==> pow(x, y[, z]) """
pass def __radd__(self, y):
""" x.__radd__(y) <==> y+x """
pass def __rdivmod__(self, y):
""" x.__rdivmod__(y) <==> divmod(y, x) """
pass def __rdiv__(self, y):
""" x.__rdiv__(y) <==> y/x """
pass def __repr__(self):
""" x.__repr__() <==> repr(x) """
pass def __rfloordiv__(self, y):
""" x.__rfloordiv__(y) <==> y//x """
pass def __rmod__(self, y):
""" x.__rmod__(y) <==> y%x """
pass def __rmul__(self, y):
""" x.__rmul__(y) <==> y*x """
pass def __rpow__(self, x, z=None):
""" y.__rpow__(x[, z]) <==> pow(x, y[, z]) """
pass def __rsub__(self, y):
""" x.__rsub__(y) <==> y-x """
pass def __rtruediv__(self, y):
""" x.__rtruediv__(y) <==> y/x """
pass def __setformat__(self, typestr, fmt):
"""
float.__setformat__(typestr, fmt) -> None You probably don't want to use this function. It exists mainly to be
used in Python's test suite. typestr must be 'double' or 'float'. fmt must be one of 'unknown',
'IEEE, big-endian' or 'IEEE, little-endian', and in addition can only be
one of the latter two if it appears to match the underlying C reality. Override the automatic determination of C-level floating point type.
This affects how floats are converted to and from binary strings.
"""
pass def __str__(self):
""" x.__str__() <==> str(x) """
pass def __sub__(self, y):
""" x.__sub__(y) <==> x-y """
pass def __truediv__(self, y):
""" x.__truediv__(y) <==> x/y """
pass def __trunc__(self, *args, **kwargs): # real signature unknown
""" Return the Integral closest to x between 0 and x. """
pass imag = property(lambda self: object(), lambda self, v: None, lambda self: None) # default
"""the imaginary part of a complex number""" real = property(lambda self: object(), lambda self, v: None, lambda self: None) # default
"""the real part of a complex number""" float
五.字符串
class str(basestring):
"""
str(object='') -> string Return a nice string representation of the object.
If the argument is a string, the return value is the same object.
"""
def capitalize(self):
""" 首字母变大写 """
"""
S.capitalize() -> string Return a copy of the string S with only its first character
capitalized.
"""
return "" def center(self, width, fillchar=None):
""" 内容居中,width:总长度;fillchar:空白处填充内容,默认无 """
"""
S.center(width[, fillchar]) -> string Return S centered in a string of length width. Padding is
done using the specified fill character (default is a space)
"""
return "" def count(self, sub, start=None, end=None):
""" 子序列个数 """
"""
S.count(sub[, start[, end]]) -> int Return the number of non-overlapping occurrences of substring sub in
string S[start:end]. Optional arguments start and end are interpreted
as in slice notation.
"""
return 0 def decode(self, encoding=None, errors=None):
""" 解码 """
"""
S.decode([encoding[,errors]]) -> object Decodes S using the codec registered for encoding. encoding defaults
to the default encoding. errors may be given to set a different error
handling scheme. Default is 'strict' meaning that encoding errors raise
a UnicodeDecodeError. Other possible values are 'ignore' and 'replace'
as well as any other name registered with codecs.register_error that is
able to handle UnicodeDecodeErrors.
"""
return object() def encode(self, encoding=None, errors=None):
""" 编码,针对unicode """
"""
S.encode([encoding[,errors]]) -> object Encodes S using the codec registered for encoding. encoding defaults
to the default encoding. errors may be given to set a different error
handling scheme. Default is 'strict' meaning that encoding errors raise
a UnicodeEncodeError. Other possible values are 'ignore', 'replace' and
'xmlcharrefreplace' as well as any other name registered with
codecs.register_error that is able to handle UnicodeEncodeErrors.
"""
return object() def endswith(self, suffix, start=None, end=None):
""" 是否以 xxx 结束 """
"""
S.endswith(suffix[, start[, end]]) -> bool Return True if S ends with the specified suffix, False otherwise.
With optional start, test S beginning at that position.
With optional end, stop comparing S at that position.
suffix can also be a tuple of strings to try.
"""
return False def expandtabs(self, tabsize=None):
""" 将tab转换成空格,默认一个tab转换成8个空格 """
"""
S.expandtabs([tabsize]) -> string Return a copy of S where all tab characters are expanded using spaces.
If tabsize is not given, a tab size of 8 characters is assumed.
"""
return "" def find(self, sub, start=None, end=None):
""" 寻找子序列位置,如果没找到,返回 -1 """
"""
S.find(sub [,start [,end]]) -> int Return the lowest index in S where substring sub is found,
such that sub is contained within S[start:end]. Optional
arguments start and end are interpreted as in slice notation. Return -1 on failure.
"""
return 0 def format(*args, **kwargs): # known special case of str.format
""" 字符串格式化,动态参数,将函数式编程时细说 """
"""
S.format(*args, **kwargs) -> string Return a formatted version of S, using substitutions from args and kwargs.
The substitutions are identified by braces ('{' and '}').
"""
pass def index(self, sub, start=None, end=None):
""" 子序列位置,如果没找到,报错 """
S.index(sub [,start [,end]]) -> int Like S.find() but raise ValueError when the substring is not found.
"""
return 0 def isalnum(self):
""" 是否是字母和数字 """
"""
S.isalnum() -> bool Return True if all characters in S are alphanumeric
and there is at least one character in S, False otherwise.
"""
return False def isalpha(self):
""" 是否是字母 """
"""
S.isalpha() -> bool Return True if all characters in S are alphabetic
and there is at least one character in S, False otherwise.
"""
return False def isdigit(self):
""" 是否是数字 """
"""
S.isdigit() -> bool Return True if all characters in S are digits
and there is at least one character in S, False otherwise.
"""
return False def islower(self):
""" 是否小写 """
"""
S.islower() -> bool Return True if all cased characters in S are lowercase and there is
at least one cased character in S, False otherwise.
"""
return False def isspace(self):
"""
S.isspace() -> bool Return True if all characters in S are whitespace
and there is at least one character in S, False otherwise.
"""
return False def istitle(self):
"""
S.istitle() -> bool Return True if S is a titlecased string and there is at least one
character in S, i.e. uppercase characters may only follow uncased
characters and lowercase characters only cased ones. Return False
otherwise.
"""
return False def isupper(self):
"""
S.isupper() -> bool Return True if all cased characters in S are uppercase and there is
at least one cased character in S, False otherwise.
"""
return False def join(self, iterable):
""" 连接 """
"""
S.join(iterable) -> string Return a string which is the concatenation of the strings in the
iterable. The separator between elements is S.
"""
return "" def ljust(self, width, fillchar=None):
""" 内容左对齐,右侧填充 """
"""
S.ljust(width[, fillchar]) -> string Return S left-justified in a string of length width. Padding is
done using the specified fill character (default is a space).
"""
return "" def lower(self):
""" 变小写 """
"""
S.lower() -> string Return a copy of the string S converted to lowercase.
"""
return "" def lstrip(self, chars=None):
""" 移除左侧空白 """
"""
S.lstrip([chars]) -> string or unicode Return a copy of the string S with leading whitespace removed.
If chars is given and not None, remove characters in chars instead.
If chars is unicode, S will be converted to unicode before stripping
"""
return "" def partition(self, sep):
""" 分割,前,中,后三部分 """
"""
S.partition(sep) -> (head, sep, tail) Search for the separator sep in S, and return the part before it,
the separator itself, and the part after it. If the separator is not
found, return S and two empty strings.
"""
pass def replace(self, old, new, count=None):
""" 替换 """
"""
S.replace(old, new[, count]) -> string Return a copy of string S with all occurrences of substring
old replaced by new. If the optional argument count is
given, only the first count occurrences are replaced.
"""
return "" def rfind(self, sub, start=None, end=None):
"""
S.rfind(sub [,start [,end]]) -> int Return the highest index in S where substring sub is found,
such that sub is contained within S[start:end]. Optional
arguments start and end are interpreted as in slice notation. Return -1 on failure.
"""
return 0 def rindex(self, sub, start=None, end=None):
"""
S.rindex(sub [,start [,end]]) -> int Like S.rfind() but raise ValueError when the substring is not found.
"""
return 0 def rjust(self, width, fillchar=None):
"""
S.rjust(width[, fillchar]) -> string Return S right-justified in a string of length width. Padding is
done using the specified fill character (default is a space)
"""
return "" def rpartition(self, sep):
"""
S.rpartition(sep) -> (head, sep, tail) Search for the separator sep in S, starting at the end of S, and return
the part before it, the separator itself, and the part after it. If the
separator is not found, return two empty strings and S.
"""
pass def rsplit(self, sep=None, maxsplit=None):
"""
S.rsplit([sep [,maxsplit]]) -> list of strings Return a list of the words in the string S, using sep as the
delimiter string, starting at the end of the string and working
to the front. If maxsplit is given, at most maxsplit splits are
done. If sep is not specified or is None, any whitespace string
is a separator.
"""
return [] def rstrip(self, chars=None):
"""
S.rstrip([chars]) -> string or unicode Return a copy of the string S with trailing whitespace removed.
If chars is given and not None, remove characters in chars instead.
If chars is unicode, S will be converted to unicode before stripping
"""
return "" def split(self, sep=None, maxsplit=None):
""" 分割, maxsplit最多分割几次 """
"""
S.split([sep [,maxsplit]]) -> list of strings Return a list of the words in the string S, using sep as the
delimiter string. If maxsplit is given, at most maxsplit
splits are done. If sep is not specified or is None, any
whitespace string is a separator and empty strings are removed
from the result.
"""
return [] def splitlines(self, keepends=False):
""" 根据换行分割 """
"""
S.splitlines(keepends=False) -> list of strings Return a list of the lines in S, breaking at line boundaries.
Line breaks are not included in the resulting list unless keepends
is given and true.
"""
return [] def startswith(self, prefix, start=None, end=None):
""" 是否起始 """
"""
S.startswith(prefix[, start[, end]]) -> bool Return True if S starts with the specified prefix, False otherwise.
With optional start, test S beginning at that position.
With optional end, stop comparing S at that position.
prefix can also be a tuple of strings to try.
"""
return False def strip(self, chars=None):
""" 移除两段空白 """
"""
S.strip([chars]) -> string or unicode Return a copy of the string S with leading and trailing
whitespace removed.
If chars is given and not None, remove characters in chars instead.
If chars is unicode, S will be converted to unicode before stripping
"""
return "" def swapcase(self):
""" 大写变小写,小写变大写 """
"""
S.swapcase() -> string Return a copy of the string S with uppercase characters
converted to lowercase and vice versa.
"""
return "" def title(self):
"""
S.title() -> string Return a titlecased version of S, i.e. words start with uppercase
characters, all remaining cased characters have lowercase.
"""
return "" def translate(self, table, deletechars=None):
"""
转换,需要先做一个对应表,最后一个表示删除字符集合
intab = "aeiou"
outtab = ""
trantab = maketrans(intab, outtab)
str = "this is string example....wow!!!"
print str.translate(trantab, 'xm')
""" """
S.translate(table [,deletechars]) -> string Return a copy of the string S, where all characters occurring
in the optional argument deletechars are removed, and the
remaining characters have been mapped through the given
translation table, which must be a string of length 256 or None.
If the table argument is None, no translation is applied and
the operation simply removes the characters in deletechars.
"""
return "" def upper(self):
"""
S.upper() -> string Return a copy of the string S converted to uppercase.
"""
return "" def zfill(self, width):
"""方法返回指定长度的字符串,原字符串右对齐,前面填充0。"""
"""
S.zfill(width) -> string Pad a numeric string S with zeros on the left, to fill a field
of the specified width. The string S is never truncated.
"""
return "" def _formatter_field_name_split(self, *args, **kwargs): # real signature unknown
pass def _formatter_parser(self, *args, **kwargs): # real signature unknown
pass def __add__(self, y):
""" x.__add__(y) <==> x+y """
pass def __contains__(self, y):
""" x.__contains__(y) <==> y in x """
pass def __eq__(self, y):
""" x.__eq__(y) <==> x==y """
pass def __format__(self, format_spec):
"""
S.__format__(format_spec) -> string Return a formatted version of S as described by format_spec.
"""
return "" def __getattribute__(self, name):
""" x.__getattribute__('name') <==> x.name """
pass def __getitem__(self, y):
""" x.__getitem__(y) <==> x[y] """
pass def __getnewargs__(self, *args, **kwargs): # real signature unknown
pass def __getslice__(self, i, j):
"""
x.__getslice__(i, j) <==> x[i:j] Use of negative indices is not supported.
"""
pass def __ge__(self, y):
""" x.__ge__(y) <==> x>=y """
pass def __gt__(self, y):
""" x.__gt__(y) <==> x>y """
pass def __hash__(self):
""" x.__hash__() <==> hash(x) """
pass def __init__(self, string=''): # known special case of str.__init__
"""
str(object='') -> string Return a nice string representation of the object.
If the argument is a string, the return value is the same object.
# (copied from class doc)
"""
pass def __len__(self):
""" x.__len__() <==> len(x) """
pass def __le__(self, y):
""" x.__le__(y) <==> x<=y """
pass def __lt__(self, y):
""" x.__lt__(y) <==> x<y """
pass def __mod__(self, y):
""" x.__mod__(y) <==> x%y """
pass def __mul__(self, n):
""" x.__mul__(n) <==> x*n """
pass @staticmethod # known case of __new__
def __new__(S, *more):
""" T.__new__(S, ...) -> a new object with type S, a subtype of T """
pass def __ne__(self, y):
""" x.__ne__(y) <==> x!=y """
pass def __repr__(self):
""" x.__repr__() <==> repr(x) """
pass def __rmod__(self, y):
""" x.__rmod__(y) <==> y%x """
pass def __rmul__(self, n):
""" x.__rmul__(n) <==> n*x """
pass def __sizeof__(self):
""" S.__sizeof__() -> size of S in memory, in bytes """
pass def __str__(self):
""" x.__str__() <==> str(x) """
pass str str
六、列表
class list(object):
"""
list() -> new empty list
list(iterable) -> new list initialized from iterable's items
"""
def append(self, p_object): # real signature unknown; restored from __doc__
""" L.append(object) -- append object to end """
pass def count(self, value): # real signature unknown; restored from __doc__
""" L.count(value) -> integer -- return number of occurrences of value """
return 0 def extend(self, iterable): # real signature unknown; restored from __doc__
""" L.extend(iterable) -- extend list by appending elements from the iterable """
pass def index(self, value, start=None, stop=None): # real signature unknown; restored from __doc__
"""
L.index(value, [start, [stop]]) -> integer -- return first index of value.
Raises ValueError if the value is not present.
"""
return 0 def insert(self, index, p_object): # real signature unknown; restored from __doc__
""" L.insert(index, object) -- insert object before index """
pass def pop(self, index=None): # real signature unknown; restored from __doc__
"""
L.pop([index]) -> item -- remove and return item at index (default last).
Raises IndexError if list is empty or index is out of range.
"""
pass def remove(self, value): # real signature unknown; restored from __doc__
"""
L.remove(value) -- remove first occurrence of value.
Raises ValueError if the value is not present.
"""
pass def reverse(self): # real signature unknown; restored from __doc__
""" L.reverse() -- reverse *IN PLACE* """
pass def sort(self, cmp=None, key=None, reverse=False): # real signature unknown; restored from __doc__
"""
L.sort(cmp=None, key=None, reverse=False) -- stable sort *IN PLACE*;
cmp(x, y) -> -1, 0, 1
"""
pass def __add__(self, y): # real signature unknown; restored from __doc__
""" x.__add__(y) <==> x+y """
pass def __contains__(self, y): # real signature unknown; restored from __doc__
""" x.__contains__(y) <==> y in x """
pass def __delitem__(self, y): # real signature unknown; restored from __doc__
""" x.__delitem__(y) <==> del x[y] """
pass def __delslice__(self, i, j): # real signature unknown; restored from __doc__
"""
x.__delslice__(i, j) <==> del x[i:j] Use of negative indices is not supported.
"""
pass def __eq__(self, y): # real signature unknown; restored from __doc__
""" x.__eq__(y) <==> x==y """
pass def __getattribute__(self, name): # real signature unknown; restored from __doc__
""" x.__getattribute__('name') <==> x.name """
pass def __getitem__(self, y): # real signature unknown; restored from __doc__
""" x.__getitem__(y) <==> x[y] """
pass def __getslice__(self, i, j): # real signature unknown; restored from __doc__
"""
x.__getslice__(i, j) <==> x[i:j] Use of negative indices is not supported.
"""
pass def __ge__(self, y): # real signature unknown; restored from __doc__
""" x.__ge__(y) <==> x>=y """
pass def __gt__(self, y): # real signature unknown; restored from __doc__
""" x.__gt__(y) <==> x>y """
pass def __iadd__(self, y): # real signature unknown; restored from __doc__
""" x.__iadd__(y) <==> x+=y """
pass def __imul__(self, y): # real signature unknown; restored from __doc__
""" x.__imul__(y) <==> x*=y """
pass def __init__(self, seq=()): # known special case of list.__init__
"""
list() -> new empty list
list(iterable) -> new list initialized from iterable's items
# (copied from class doc)
"""
pass def __iter__(self): # real signature unknown; restored from __doc__
""" x.__iter__() <==> iter(x) """
pass def __len__(self): # real signature unknown; restored from __doc__
""" x.__len__() <==> len(x) """
pass def __le__(self, y): # real signature unknown; restored from __doc__
""" x.__le__(y) <==> x<=y """
pass def __lt__(self, y): # real signature unknown; restored from __doc__
""" x.__lt__(y) <==> x<y """
pass def __mul__(self, n): # real signature unknown; restored from __doc__
""" x.__mul__(n) <==> x*n """
pass @staticmethod # known case of __new__
def __new__(S, *more): # real signature unknown; restored from __doc__
""" T.__new__(S, ...) -> a new object with type S, a subtype of T """
pass def __ne__(self, y): # real signature unknown; restored from __doc__
""" x.__ne__(y) <==> x!=y """
pass def __repr__(self): # real signature unknown; restored from __doc__
""" x.__repr__() <==> repr(x) """
pass def __reversed__(self): # real signature unknown; restored from __doc__
""" L.__reversed__() -- return a reverse iterator over the list """
pass def __rmul__(self, n): # real signature unknown; restored from __doc__
""" x.__rmul__(n) <==> n*x """
pass def __setitem__(self, i, y): # real signature unknown; restored from __doc__
""" x.__setitem__(i, y) <==> x[i]=y """
pass def __setslice__(self, i, j, y): # real signature unknown; restored from __doc__
"""
x.__setslice__(i, j, y) <==> x[i:j]=y Use of negative indices is not supported.
"""
pass def __sizeof__(self): # real signature unknown; restored from __doc__
""" L.__sizeof__() -- size of L in memory, in bytes """
pass __hash__ = None
七、元组
class tuple(object):
"""
tuple() -> empty tuple
tuple(iterable) -> tuple initialized from iterable's items If the argument is a tuple, the return value is the same object.
"""
def count(self, value): # real signature unknown; restored from __doc__
""" T.count(value) -> integer -- return number of occurrences of value """
return 0 def index(self, value, start=None, stop=None): # real signature unknown; restored from __doc__
"""
T.index(value, [start, [stop]]) -> integer -- return first index of value.
Raises ValueError if the value is not present.
"""
return 0 def __add__(self, y): # real signature unknown; restored from __doc__
""" x.__add__(y) <==> x+y """
pass def __contains__(self, y): # real signature unknown; restored from __doc__
""" x.__contains__(y) <==> y in x """
pass def __eq__(self, y): # real signature unknown; restored from __doc__
""" x.__eq__(y) <==> x==y """
pass def __getattribute__(self, name): # real signature unknown; restored from __doc__
""" x.__getattribute__('name') <==> x.name """
pass def __getitem__(self, y): # real signature unknown; restored from __doc__
""" x.__getitem__(y) <==> x[y] """
pass def __getnewargs__(self, *args, **kwargs): # real signature unknown
pass def __getslice__(self, i, j): # real signature unknown; restored from __doc__
"""
x.__getslice__(i, j) <==> x[i:j] Use of negative indices is not supported.
"""
pass def __ge__(self, y): # real signature unknown; restored from __doc__
""" x.__ge__(y) <==> x>=y """
pass def __gt__(self, y): # real signature unknown; restored from __doc__
""" x.__gt__(y) <==> x>y """
pass def __hash__(self): # real signature unknown; restored from __doc__
""" x.__hash__() <==> hash(x) """
pass def __init__(self, seq=()): # known special case of tuple.__init__
"""
tuple() -> empty tuple
tuple(iterable) -> tuple initialized from iterable's items If the argument is a tuple, the return value is the same object.
# (copied from class doc)
"""
pass def __iter__(self): # real signature unknown; restored from __doc__
""" x.__iter__() <==> iter(x) """
pass def __len__(self): # real signature unknown; restored from __doc__
""" x.__len__() <==> len(x) """
pass def __le__(self, y): # real signature unknown; restored from __doc__
""" x.__le__(y) <==> x<=y """
pass def __lt__(self, y): # real signature unknown; restored from __doc__
""" x.__lt__(y) <==> x<y """
pass def __mul__(self, n): # real signature unknown; restored from __doc__
""" x.__mul__(n) <==> x*n """
pass @staticmethod # known case of __new__
def __new__(S, *more): # real signature unknown; restored from __doc__
""" T.__new__(S, ...) -> a new object with type S, a subtype of T """
pass def __ne__(self, y): # real signature unknown; restored from __doc__
""" x.__ne__(y) <==> x!=y """
pass def __repr__(self): # real signature unknown; restored from __doc__
""" x.__repr__() <==> repr(x) """
pass def __rmul__(self, n): # real signature unknown; restored from __doc__
""" x.__rmul__(n) <==> n*x """
pass def __sizeof__(self): # real signature unknown; restored from __doc__
""" T.__sizeof__() -- size of T in memory, in bytes """
pass tuple
八、字典
class dict(object):
"""
dict() -> new empty dictionary
dict(mapping) -> new dictionary initialized from a mapping object's
(key, value) pairs
dict(iterable) -> new dictionary initialized as if via:
d = {}
for k, v in iterable:
d[k] = v
dict(**kwargs) -> new dictionary initialized with the name=value pairs
in the keyword argument list. For example: dict(one=1, two=2)
""" def clear(self): # real signature unknown; restored from __doc__
""" 清除内容 """
""" D.clear() -> None. Remove all items from D. """
pass def copy(self): # real signature unknown; restored from __doc__
""" 浅拷贝 """
""" D.copy() -> a shallow copy of D """
pass @staticmethod # known case
def fromkeys(S, v=None): # real signature unknown; restored from __doc__
"""
dict.fromkeys(S[,v]) -> New dict with keys from S and values equal to v.
v defaults to None.
"""
pass def get(self, k, d=None): # real signature unknown; restored from __doc__
""" 根据key获取值,d是默认值 """
""" D.get(k[,d]) -> D[k] if k in D, else d. d defaults to None. """
pass def has_key(self, k): # real signature unknown; restored from __doc__
""" 是否有key """
""" D.has_key(k) -> True if D has a key k, else False """
return False def items(self): # real signature unknown; restored from __doc__
""" 所有项的列表形式 """
""" D.items() -> list of D's (key, value) pairs, as 2-tuples """
return [] def iteritems(self): # real signature unknown; restored from __doc__
""" 项可迭代 """
""" D.iteritems() -> an iterator over the (key, value) items of D """
pass def iterkeys(self): # real signature unknown; restored from __doc__
""" key可迭代 """
""" D.iterkeys() -> an iterator over the keys of D """
pass def itervalues(self): # real signature unknown; restored from __doc__
""" value可迭代 """
""" D.itervalues() -> an iterator over the values of D """
pass def keys(self): # real signature unknown; restored from __doc__
""" 所有的key列表 """
""" D.keys() -> list of D's keys """
return [] def pop(self, k, d=None): # real signature unknown; restored from __doc__
""" 获取并在字典中移除 """
"""
D.pop(k[,d]) -> v, remove specified key and return the corresponding value.
If key is not found, d is returned if given, otherwise KeyError is raised
"""
pass def popitem(self): # real signature unknown; restored from __doc__
""" 获取并在字典中移除 """
"""
D.popitem() -> (k, v), remove and return some (key, value) pair as a
2-tuple; but raise KeyError if D is empty.
"""
pass def setdefault(self, k, d=None): # real signature unknown; restored from __doc__
""" 如果key不存在,则创建,如果存在,则返回已存在的值且不修改 """
""" D.setdefault(k[,d]) -> D.get(k,d), also set D[k]=d if k not in D """
pass def update(self, E=None, **F): # known special case of dict.update
""" 更新
{'name':'alex', 'age': 18000}
[('name','sbsbsb'),]
"""
"""
D.update([E, ]**F) -> None. Update D from dict/iterable E and F.
If E present and has a .keys() method, does: for k in E: D[k] = E[k]
If E present and lacks .keys() method, does: for (k, v) in E: D[k] = v
In either case, this is followed by: for k in F: D[k] = F[k]
"""
pass def values(self): # real signature unknown; restored from __doc__
""" 所有的值 """
""" D.values() -> list of D's values """
return [] def viewitems(self): # real signature unknown; restored from __doc__
""" 所有项,只是将内容保存至view对象中 """
""" D.viewitems() -> a set-like object providing a view on D's items """
pass def viewkeys(self): # real signature unknown; restored from __doc__
""" D.viewkeys() -> a set-like object providing a view on D's keys """
pass def viewvalues(self): # real signature unknown; restored from __doc__
""" D.viewvalues() -> an object providing a view on D's values """
pass def __cmp__(self, y): # real signature unknown; restored from __doc__
""" x.__cmp__(y) <==> cmp(x,y) """
pass def __contains__(self, k): # real signature unknown; restored from __doc__
""" D.__contains__(k) -> True if D has a key k, else False """
return False def __delitem__(self, y): # real signature unknown; restored from __doc__
""" x.__delitem__(y) <==> del x[y] """
pass def __eq__(self, y): # real signature unknown; restored from __doc__
""" x.__eq__(y) <==> x==y """
pass def __getattribute__(self, name): # real signature unknown; restored from __doc__
""" x.__getattribute__('name') <==> x.name """
pass def __getitem__(self, y): # real signature unknown; restored from __doc__
""" x.__getitem__(y) <==> x[y] """
pass def __ge__(self, y): # real signature unknown; restored from __doc__
""" x.__ge__(y) <==> x>=y """
pass def __gt__(self, y): # real signature unknown; restored from __doc__
""" x.__gt__(y) <==> x>y """
pass def __init__(self, seq=None, **kwargs): # known special case of dict.__init__
"""
dict() -> new empty dictionary
dict(mapping) -> new dictionary initialized from a mapping object's
(key, value) pairs
dict(iterable) -> new dictionary initialized as if via:
d = {}
for k, v in iterable:
d[k] = v
dict(**kwargs) -> new dictionary initialized with the name=value pairs
in the keyword argument list. For example: dict(one=1, two=2)
# (copied from class doc)
"""
pass def __iter__(self): # real signature unknown; restored from __doc__
""" x.__iter__() <==> iter(x) """
pass def __len__(self): # real signature unknown; restored from __doc__
""" x.__len__() <==> len(x) """
pass def __le__(self, y): # real signature unknown; restored from __doc__
""" x.__le__(y) <==> x<=y """
pass def __lt__(self, y): # real signature unknown; restored from __doc__
""" x.__lt__(y) <==> x<y """
pass @staticmethod # known case of __new__
def __new__(S, *more): # real signature unknown; restored from __doc__
""" T.__new__(S, ...) -> a new object with type S, a subtype of T """
pass def __ne__(self, y): # real signature unknown; restored from __doc__
""" x.__ne__(y) <==> x!=y """
pass def __repr__(self): # real signature unknown; restored from __doc__
""" x.__repr__() <==> repr(x) """
pass def __setitem__(self, i, y): # real signature unknown; restored from __doc__
""" x.__setitem__(i, y) <==> x[i]=y """
pass def __sizeof__(self): # real signature unknown; restored from __doc__
""" D.__sizeof__() -> size of D in memory, in bytes """
pass __hash__ = None dict
______________________________________________________________________________________________________________________________________________________________________________________
实例操作:
int
##########################int##########################
bit_length()
bit_length()返回表示该数字的时占用的最少位数
语法:int.bit_length()
Num=15 #15,(8 4 2 1) 0000 1111 占4位
A=Num.bit_length()
print(A) abs()
print (abs(-15)) #绝对值 引用int.__abs__() Num=15
+ 加号
A=Num.__add__(15) #等同于15+15
print (A) A=Num.__and__(14) #与运算 等同于&符号 15&14
print(A) A=Num.__bool__() #等同于 Num != 0 返回True和False
print(A) A=Num.__divmod__(10) #等同于15/10,区别在于返回元组
print(A)
print (15/10) A=Num.__floordiv__(10) #和divmod区别在于 floordiv只取商
print(A)
print(15//10) A=Num.__getattribute__() #反射用
print(A) A=Num.__getnewargs__() #内部调用 __new__方法或创建对象时传入参数使用
print(A) int.__index__( ) #index,是当前对象如果作为某个序列的 索引 时,自动会执行该对象的 __index__ 方法,将其返回值作为 索引
x=[1,2,3,4,5,6,7]
y=5
z=1
A=x[z:y]
print(A) int.__invert__() #加1取反 等同于~10 int.__pow__() #次幂
A=Num.__pow__(2) #等同于pow(15,2)
print(A) A=Num.__repr__() #将数字转换为字符串
print(type(A)) Python Int
Python Int
字符串
##########################字符串##########################
Python capitalize()
Python capitalize()将字符串的第一个字母变成大写,其他字母变小写。对于 8 位字节编码需要根据本地环境。
语法:str.capitalize()
Name = 'chen'
A = Name.capitalize()
print (A) Python center()
Python center() 返回一个原字符串居中,并使用空格填充至长度 width 的新字符串。默认填充字符为空格
语法:str.center(width[, fillchar])
A = Name.center(20,'#')
print (A) Python count()
Python count() 方法用于统计字符串里某个字符出现的次数。可选参数为在字符串搜索的开始与结束位置。
语法:str.count(sub, start= 0,end=len(string))
Name = 'aabbbbb2222ddddsaaadffffsss'
A = Name.count('a',0,10)
print (A) Python encode()
Python encode() 方法以 encoding 指定的编码格式编码字符串。errors参数可以指定不同的错误处理方案。
语法:str.encode(encoding='UTF-8',errors='strict')
Name= "陈金彭"
A = Name.encode('gbk')
print(A) Python endswith()
方法用于判断字符串是否以指定后缀结尾,如果以指定后缀结尾返回True,否则返回False。可选参数"start"与"end"为检索字符串的开始与结束位置。
语法:str.endswith(suffix[, start[, end]])
A = Name.endswith('e',0,3)
print (A) Python expandtabs()
Python expandtabs() 方法把字符串中的 tab 符号('\t')转为空格,默认的空格数 tabsize 是 8。
语法:str.expandtabs(tabsize=8)
Name = 'ch\ten'
A = Name.expandtabs(tabsize=100)
print (A) Python find()
Python find() 方法检测字符串中是否包含子字符串 str ,如果指定 beg(开始) 和 end(结束) 范围,则检查是否包含在指定范围内,如果包含子字符串返回开始的索引值,否则返回-1。
语法:str.find(str, beg=0, end=len(string))
Name = 'abcaaaahhhhbbbbcccc'
A = Name.find('c',10,16)
print (A) python format()字符串格式化
Name = "陈金彭"
Age = 17
print ('My Name is {0},Age is {1}'.format(Name,Age)) Python index()
Python index() 方法检测字符串中是否包含子字符串 str ,如果指定 beg(开始) 和 end(结束) 范围,则检查是否包含在指定范围内,该方法与 python find()方法一样,只不过如果str不在 string中会报一个异常。
语法:str.index(str, beg=0, end=len(string))
A = Name.index('g')
print (A) Python isalnum()
Python isalnum() 方法检测字符串是否由字母和数字组成。
语法:str.isa1num()
A = Name.isalnum()
print (A) Python isalpha()
Python isalpha() 方法检测字符串是否只由字母组成。
语法:str.isalpha()
Name = ''
A = Name.isalpha()
print (A) Python isdigit()
Python isdigit() 方法检测字符串是否只由数字组成。
语法:str.isdigit()
A = Name.isdigit()
print (A) Python islower()
Python islower() 方法检测字符串是否由小写字母组成。
语法:str.islower()
A = Name.islower()
print (A) Python isspace()
Python isspace() 方法检测字符串是否只由空格组成。
语法:str.isspace()
Name = ' '
A = Name.isspace()
print (A) Python istitle()
Python istitle() 方法检测字符串中所有的单词拼写首字母是否为大写,且其他字母为小写。
语法:str.istitle()
Name = 'Aaad Aa'
A = Name.istitle()
print (A) Python isupper()
Python isupper() 方法检测字符串中所有的字母是否都为大写。
语法:str.isupper()
Name='CHEN'
A = Name.isupper()
print (A) Python isdecimal()
Python isdecimal() 方法检查字符串是否只包含十进制字符。这种方法只存在于unicode对象。注意:定义一个十进制字符串,只需要在字符串前添加 'u' 前缀即可。
语法:str.isdecimal()
Name = ''
A=Name.isdecimal()
print (A) Python isnumeric()
Python isnumeric() 方法检测字符串是否只由数字组成。这种方法是只针对unicode对象。注:定义一个字符串为Unicode,只需要在字符串前添加 'u' 前缀即可,具体可以查看本章节例子
语法:str.isnumeric()
Name = ''
A=Name.isnumeric()
print (A) Python join()
Python join() 方法用于将序列中的元素以指定的字符连接生成一个新的字符串。
语法:str.join(sequence)
A = '陈'
B = '金彭'
print(''.join([A,B])) Python ljust()
Python ljust() 方法返回一个原字符串左对齐,并使用空格填充至指定长度的新字符串。如果指定的长度小于原字符串的长度则返回原字符串
语法:str.ljust(width[, fillchar])
A = Name.ljust(5,'#')
print (A) Python lower()
Python lower() 方法转换字符串中所有大写字符为小写。
语法:str.lower()
Name='CHEN'
A = Name.lower()
print (A) Python lstrip()
Python lstrip() 方法用于截掉字符串左边的空格或指定字符。
语法;str.lstrip([chars])
Name=' chenjin peng '
A = Name.lstrip()
print (A) ###maketrans以及translate方法解释:
Python maketrans() 方法用于创建字符映射的转换表,对于接受两个参数的最简单的调用方式,第一个参数是字符串,表示需要转换的字符,第二个参数也是字符串表示转换的目标。注:两个字符串的长度必须相同,为一一对应的关系。
Python translate() 方法根据参数table给出的表(包含 256 个字符)转换字符串的字符, 要过滤掉的字符放到 del 参数中。
A='abcde'
B=''
AA = str.maketrans(A,B)
CC='my name is chen...abe'
print(CC.translate(AA)) Python upper()
Python upper() 将字符串转换为全大写(字符串:ASCII字符)
语法:str.upper()
A = Name.upper()
print (A) partition()
partition() 方法用来根据指定的分隔符将字符串进行分割。如果字符串包含指定的分隔符,则返回一个3元的元组,第一个为分隔符左边的子串,第二个为分隔符本身,第三个为分隔符右边的子串。partition() 方法是在2.5版中新增的
语法:str.partition(str)
A=Name.partition('e')
print(type(A)) Python replace()
Python replace() 方法把字符串中的 old(旧字符串) 替换成 new(新字符串),如果指定第三个参数max,则替换不超过 max 次。
语法:str.replace(old, new[, max])
A=Name.replace('h','a')
print (A) Python rfind()
Python rfind() 返回字符串最后一次出现的位置,如果没有匹配项则返回-1。
语法str.rfind(str, beg=0 end=len(string))
A=Name.rfind('n',0,4)
print(A) Python rindex()
Python rindex() 返回子字符串 str 在字符串中最后出现的位置,如果没有匹配的字符串会报异常,你可以指定可选参数[beg:end]设置查找的区间。
语法:str.rindex(str, beg=0 end=len(string))
A=Name.rindex('c')
print (A) Python rjust()
Python rjust() 返回一个原字符串右对齐,并使用空格填充至长度 width 的新字符串。如果指定的长度小于字符串的长度则返回原字符串
语法:str.rjust(width[, fillchar])
A=Name.rjust(5,'#')
print (A) Python.rpartition()
Python.rpartition() 分割字符串,(从右往左)返回元组
语法:str.rpartition(str)
A=Name.rpartition('h')
print (A) Python splitlines()
Python splitlines() 按照行分隔,返回一个包含各行作为元素的列表,如果 num 指定则仅切片 num 个行.
语法:str.splitlines( num=string.count('\n'))
Name = 'chen jin peng\nqiu lu nan'
print (Name.splitlines()) Python startswith()
Python startswith() 方法用于检查字符串是否是以指定子字符串开头,如果是则返回 True,否则返回 False。如果参数 start 和 end 指定值,则在指定范围内检查。
语法:str.startswith(str, beg=0,end=len(string));
A=Name.startswith('c')
print(A) Python strip()
Python strip() 方法用于移除字符串头尾指定的字符(默认为空格)。
语法:str.strip([chars]);
Name=' chen\n '
A=Name.strip()
print (A) Python swapcase()
Python swapcase() 方法用于对字符串的大小写字母进行转换。
语法:str.swapcase();
Name = 'CHEN'
A=Name.swapcase()
print(A) Python title()
Python title() 方法返回"标题化"的字符串,就是说所有单词都是以大写开始,其余字母均为小写(见 istitle())。
语法str.title();
Name='chen_jinpeng'
A=Name.title()
print(A) Python upper()
Python upper() 方法将字符串中的小写字母转为大写字母。
语法:str.upper()
A=Name.upper()
print(A) Python zfill()
Python zfill() 方法返回指定长度的字符串,原字符串右对齐,前面填充0。
语法:str.zfill(width)
print (Name.zfill(80))
print(Name.zfill(79))
Python Unicode
列表
##########################列表##########################
Name = ['chen','alex','wu']
append()
append() 方法用于在列表末尾添加新的对象。
语法:list.append(obj)
Name.append('65年哥')
print (Name) clear()
clear()方法用户删除所有列表中的元素
语法:list.clear()
Name.clear()
print (Name) copy()方法
copy()方法用户copy列表中的元素,【浅拷贝】
语法:list.copy()
Name2=Name.copy()
print(Name2) count() 方法
count() 方法用于统计某个元素在列表中出现的次数。
语法:list.count(obj)
A=Name.count('alex')
print(A) extend()
extend() 函数用于在列表末尾一次性追加另一个序列中的多个值(用新列表扩展原来的列表)。
语法:list.extend(seq)
Name2=['猴子','瘸子']
Name.extend(Name2)
print(Name) index()
index() 函数用于从列表中找出某个值第一个匹配项的索引位置。
语法:list.index(obj)
A=Name.index('wu')
print(A) insert()
insert() 函数用于将指定对象插入列表。
语法:list.insert(index, obj)
Name.insert(1,'65武姐姐')
print(Name) pop()
pop() 函数用于移除列表中的一个元素(默认最后一个元素),并且返回该元素的值。
语法list.pop(obj=list[-1])
A=Name.pop()
print(A,Name) remove()
remove() 函数用于移除列表中某个值的第一个匹配项。
语法:list.remove(obj)
Name.remove('alex')
print(Name) reverse()
reverse() 函数用于反向列表中元素。
语法:list.reverse()
Name.reverse()
print(Name) sort()
sort() 函数用于对原列表进行排序,如果指定参数,则使用比较函数指定的比较函数。
语法:list.sort([func])
Name=['','','A','B','a','b','一','二','!','%']
Name.sort()
print(Name)
Python List
元组
##########################元组##########################
Name=('chen','wu','alex','chen')
count()
count() 方法用于统计某个元素在元组中出现的次数。
语法:tuple.count(obj)
A=Name.count('chen')
print(A) index()
index() 函数用于从列表中找出某个值第一个匹配项的索引位置。
语法:tuple.index(obj)
A=Name.index('alex')
print(A)
Python Tuple
字典
##########################字典########################## Dic={'k1':'value1','k2':'value2'} clear()
clear() 函数用于删除字典内所有元素。
语法:dict.clear()
Dic.clear()
print(Dic) dict.copy()
Python 字典(Dictionary) copy() 函数返回一个字典的浅复制。
何为浅复制:(浅拷贝 在副本中替换值的时候 原字典不受影响, 如果修改或者删除了深层(非第一层)的值 原始的字典也会改变,为了避免这种情况,就使用深拷贝)
语法:dict.copy()
Dic={'k1':{'value1':['aaaa',123]},'k2':'value2'}
Dic2=Dic.copy()
# print(Dic2)
Dic2['k1']['value1'][1]=1234
Dic2['k1']['value1'].remove('aaaa')
print(Dic2)
print(Dic)
另一案例
a={'k1':'v1','k2':[11,22,33]}
print(id(a),a)
print(id(a['k2']),a['k2'])
b=dict.copy(a)
print(id(b),b)
print(id(b['k2']),b['k2'])
print(id(a['k1']),a['k1'])
print(id(b['k1']),b['k1'])
print(a.keys(),id(a.keys()))
print(b.keys(),id(b.keys())) fromkeys()
Python 字典(Dictionary) fromkeys() 函数用于创建一个新字典,以序列seq中元素做字典的键,value为字典所有键对应的初始值。
语法:dict.fromkeys(seq[, value]))
Seq=['name','age','sex']
Dic=dict.fromkeys(Seq)
print(Dic)
Dic=dict.fromkeys(Seq,10)
print(Dic) get()
Python 字典(Dictionary) get() 函数返回指定键的值,如果值不在字典中返回默认值None。
语法:dict.get(key, default=None)
A=Dic.get('k1')
print(A) items()
Python 字典(Dictionary) items() 函数以列表返回可遍历的(键, 值) 元组数组。
语法:dict.items()
A=Dic.items()
print(A) keys()
Python 字典(Dictionary) keys() 函数以列表返回一个字典所有的键。
语法:dict.keys()
A=Dic.keys()
print(A) pop()
pop() 函数用于移除字典中指定的keys,并将其value删除,并且返回该元素的值。
语法:dict.pop(obj)
A=Dic.pop('k1')
print(A,Dic) popitem()
dict.popitem()方法删除字典中随机的键,值
语法:dict.popitem()
A=Dic.popitem()
print(A,Dic) setdefault()
Python 字典(Dictionary) setdefault() 函数和get()方法类似,如果键存在,打印value,如果键不存在于字典中,将会添加键并将值设为默认值。
语法:dict.setdefault(key, default=None)
A=Dic.setdefault('k3','noexit')
print(A,Dic) update()
Python 字典(Dictionary) update() 函数把字典dict2的键/值对更新到dict里。
语法:dict.update(dict2)
A={'name','chen'}
B={'age',''}
A.update(B)
print(A) values()
Python 字典(Dictionary) values() 函数以列表返回字典中的所有值。
语法:dict.values()
A=Dic.values()
print(A) dict.__contains__() #查找字符串是否存在字典中的keys,返回True或者False
Search='k1'
print(Dic)
A=Dic.__contains__(Search)
print(A)
Python Dict
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