Python错误:UnboundLocalError:在赋值之前引用的局部变量“f”。

I'm trying to process some files using threading in Python.Some threads work fine with no error but some through the below exception

我正在尝试处理一些在Python中使用线程的文件。有些线程可以正常工作，但有些线程可以通过下面的异常来运行。

Exception in thread Thread-27484:
Traceback (most recent call last):
  File "/usr/lib/python2.7/threading.py", line 551, in __bootstrap_inner
    self.run()
  File "/usr/lib/python2.7/threading.py", line 504, in run
    self.__target(*self.__args, **self.__kwargs)
  File "script.py", line 62, in ProcessFile
    if f is not None:
UnboundLocalError: local variable 'f' referenced before assignment

while running my program

在运行我的程序

Here is Python function

这是Python函数

def ProcessFile(fieldType,filePath,data):
    try:
        if fieldType == 'email':
            fname = 'email.txt'
        else:
            fname = 'address.txt'
        f1 = open(fname,'wb')
        for r in data[1:]:
            r[1] = randomData(fieldType)
            f1.write(r[1])
        f1.close()

        f = open(filePath,'wb')

        writer = csv.writer(f)
        writer.writerows(data)
        f.close()
        try:
            shutil.move(filePath,processedFileDirectory)
        except:
            if not os.path.exists(fileAlreadyExistDirectory):
                os.makedirs(fileAlreadyExistDirectory)
            shutil.move(filePath,fileAlreadyExistDirectory)
    finally:
        if f is not None:
            f.close()

Here is how i'm calling the above function through threading

下面是我如何通过线程调用上面的函数。

t = Thread(target=ProcessFile,args=(fieldType,filePath,data))
        t.start()

1 个解决方案

#1

Obviously, you got an exception somewhere in your 'try' clause before you actually wrote anything to f. So not only does f not hold a value, it doesn't even exist.

显然，在你写任何东西到f之前，你在你的“try”子句中有一个例外，所以不仅f没有值，它甚至不存在。

Simplest fix is to add

最简单的解决方法是添加。

f = None

above the try clause. But probably, you are not expecting an exception that early, so maybe you should check the data you are sending this function

以上条款。但是很可能，您不希望在早期出现异常，所以您应该检查发送该函数的数据。

#1