common.py 文件源码

def fspath(path):
        """
        Return the string representation of the path.
        If str or bytes is passed in, it is returned unchanged.
        This code comes from PEP 519, modified to support earlier versions of
        python.

        This is required for python < 3.6.
        """
        if isinstance(path, (py.builtin.text, py.builtin.bytes)):
            return path

        # Work from the object's type to match method resolution of other magic
        # methods.
        path_type = type(path)
        try:
            return path_type.__fspath__(path)
        except AttributeError:
            if hasattr(path_type, '__fspath__'):
                raise
            try:
                import pathlib
            except ImportError:
                pass
            else:
                if isinstance(path, pathlib.PurePath):
                    return py.builtin.text(path)

            raise TypeError("expected str, bytes or os.PathLike object, not "
                            + path_type.__name__)