validation.py 文件源码

def str_is_existing_file(path: str) -> str:
    """
    >>> import tempfile

    >>> with tempfile.TemporaryFile() as f:
    ...     str_is_existing_file(f.name) == f.name
    True

    >>> str_is_existing_file('/home')
    Traceback (most recent call last):
    argparse.ArgumentTypeError: Given path is not an existing file.

    >>> str_is_existing_file('')
    Traceback (most recent call last):
    argparse.ArgumentTypeError: Given path is not an existing file.

    >>> str_is_existing_file('/non/existing/file')
    Traceback (most recent call last):
    argparse.ArgumentTypeError: Given path is not an existing file.
    """
    if isfile(path):
        return path
    else:
        raise ArgumentTypeError("Given path is not an existing file.")