NameError：未定义全局名称“message”

I am new at python, currently I am working on a GPS tracker with that interacts with Google maps using an Arduino Uno. I am getting this error and it is not letting me run the .py script for my tcpServer this is the whole script.

我是python的新手,目前我正在开发一款GPS跟踪器,它使用Arduino Uno与Google地图进行交互。我收到此错误,并没有让我运行我的tcpServer的.py脚本这是整个脚本。

#!/usr/bin/env python

import socket
import MySQLdb

TCP_IP = 'my machine IP'
TCP_PORT = 32000
BUFFER_SIZE = 40

# ClearDB. Deletes the entire tracking table

def ClearDB(curs,d ):
    curs.execute ("""
        INSERT INTO gmaptracker (lat, lon)
        VALUES (0.0,0.0)""")
    d.commit()

# Connect to the mySQL Database

def tServer():
    try:

        db = MySQLdb.connect (host = "my host",
            user = "my user",
            passwd = "my password",
            db = "gmap" )
    except MySQLdb.Error, e:
        print "Error %d: %s" %(e.args[0], e.args[1])
        sys.exit(1);

    cursor = db.cursor()

    # Start with a fresh tracking table

    ClearDB(cursor,db)

    # Set up listening Socket

    try:
        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        s.bind((TCP_IP, TCP_PORT))
        print "Listening...."
        s.listen(1)
        conn, addr = s.accept()
        print 'Accepted connection from address:', addr

    except socket.error (message):
        if s:
            s.close()
            print "Could not open socket: " + message
            cursor.close()
            conn.close()
            db.close()
            sys.exit(1)

    try:
        while 1:
            data = conn.recv(BUFFER_SIZE)
            if not data:break

            str1,str2 = data.split("Long: ")
            str1 = str1.split("Lat: ")[1]
            latitude = float(str1)
            longitude = float(str2)
            cursor.execute ("""
                INSERT INTO gmaptracker (lat, lon)
                VALUES (%s,%s)""", (latitude,longitude))

            db.commit()

    except KeyboardInterrupt:
        ClearDB(cursor,db);
        cursor.close()
        conn.close()
        db.close()

if __name__ == '__main__':
   tServer()

and this is the error that I am getting

这是我得到的错误

Traceback (most recent call last):
 File "tcpServer.py", line 79, in <module>
   tServer()
 File "tcpServer.py", line 48, in tServer
   except socket.error(message):
NameError: global name 'message' is not defined

If anyone can help me figure this out I would greatly appreciate it, as I said I am new at python I am also running python 2.7 if that helps. Thanks in advance

如果有人可以帮我解决这个问题,我会非常感激,因为我说我是python的新手我也在运行python 2.7如果有帮助的话。提前致谢

1 个解决方案

#1

You are not using the correct syntax for catching an exception. Instead, use:

您没有使用正确的语法来捕获异常。相反,使用:

except socket.error as serror:
    message = serror.message

The socket.error exception has two extra attributes, errno and message. Older code used to catch it like this:

socket.error异常有两个额外的属性,errno和message。用于捕获它的旧代码如下:

except socket.error, (value, message):

because in Python 2 you can treat an exception like a tuple and unpack it, but that's gone in Python 3 and should really not be used.

因为在Python 2中你可以像处理元组一样处理异常并将其解压缩,但是这在Python 3中已经消失了,并且应该不会被使用。

Moreover, the older except exceptiontype, targetvariable: has been replaced by the except exceptiontype as targetvariable: syntax as that is less ambiguous when you try to catch more than one exception type in the same statement.

此外,旧的除了exceptiontype,targetvariable:已被except exceptiontype替换为targetvariable:语法,因为当你尝试在同一语句中捕获多个异常类型时,这种模式不那么模糊。

When an exception is thrown, the normal flow of code is interrupted; instead the flow 'jumps' to the exception handler. Because of this jump, you have another problem in your code. In the exception handler you refer to conn.close(), but the variable conn is defined after the point where the socket exception will be thrown (the various socket operations). This will result in a NameError. In this case, there is no path through your code that'll result in conn being assigned an open socket connection, you can remove the conn.close() line altogether.

抛出异常时,正常的代码流被中断;相反,流'跳转'到异常处理程序。由于这种跳转,您的代码中还有另一个问题。在异常处理程序中,您引用conn.close(),但变量conn是在抛出套接字异常的位置(各种套接字操作)之后定义的。这将导致NameError。在这种情况下,代码中没有路径会导致conn被分配一个打开的套接字连接,你可以完全删除conn.close()行。

If there was a need to call .close() on conn, you'd need to detect if it was set in the first place. Set it to None, beforehand, then call .close() only if conn is no longer None:

如果需要在conn上调用.close(),则需要检测它是否首先设置。事先将其设置为None,然后仅在conn不再为None时调用.close():

conn = None
try:
    # ... do stuff ...
    conn, addr = s.accept()
    # ... do more stuff
except socket.error as serror:
    # test if `conn` was set
    if conn is not None:
        conn.close()

#1