def isfile():
        """
        Check if this file path refers to a regular file.

        @return: C{True} if the file at this file path is a regular file,
            C{False} otherwise.
        """

        Check if this file path refers to a regular file.

        @return: C{True} if the file at this file path is a regular file,
            C{False} otherwise.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/python/filepath.py