取消链接后，为什么重新调用了sys.stdout.write（）方法？

我写了一个tee（）类，该类基于Triptych在https://stackoverflow.com/questions/616645/how-do-i-duplicate-sys-stdout-上的答案将stdout重定向到终端和文件 到 python中的日志文件。

它在我的程序运行的前几次有效，但在第3次运行时有效：

  File "C:\Users\Dave\data\Code\Python\lib\nerdlib.py", line 351, in write
    with open(self.name, "a",  encoding="utf-8") as f:

TypeError: expected str, bytes or os.PathLike object, not NoneType

看来，即使在我执行了sys.stdout = self.old_stdout（将执行向量还原到它从其开始的位置）之后，仍然以某种方式调用了我的write方法（在这种情况下会出现错误）。

但是为什么我的方法仍然被调用？

在Spyder开发环境中会发生此错误-不确定是否相关。

代码在下面-很简单。

# based on Triptych's answer at https://stackoverflow.com/questions/616645/how-do-i-duplicate-sys-stdout-to-a-log-file-in-python
class tee():
    ''' Tees stdout to both a log file and the terminal.

        if append is True (default), appends to existing file

        if stderr is True (default), tees stederr to same file

        Usage:
            t = tee("filename.txt")
            ...
            print(1, 2, 3)
            ...
            t.__del__() # returns sys.stdout to original state
    '''

    def __init__(self, filepath, append=True, stderr=True):

        self.old_stdout = sys.stdout
        self.old_stderr = sys.stderr
        self.name = filepath

        if (not append) or (not os.path.exists(self.name)):
            makeEmptyFile(self.name)

        sys.stdout = self

        if stderr:
            sys.stderr = self

    def write(self, text):

        self.old_stdout.write(text)

        # open file, write, then close it again (slow, but safe - permits other processes to write to same file)
        with open(self.name, "a",  encoding="utf-8") as f:
           f.write(text)

    def flush(self):
        pass

    def stop(self):
        sys.stdout = self.old_stdout
        sys.stdout = self.old_stderr
        self.name = None

    def __del__(self):
        self.stop()

问题来源：stackoverflow