def list(self, path, protocol):
        """
        Retrieve a file listing into the given protocol instance.

        This method issues the 'LIST' FTP command.

        @param path: path to get a file listing for.
        @param protocol: a L{Protocol} instance, probably a
            L{FTPFileListProtocol} instance.  It can cope with most common file
            listing formats.

        @return: L{Deferred}
        """
        if path is None:
            path = ''
        return self.receiveFromConnection(['LIST ' + self.escapePath(path)], protocol)

        Retrieve a file listing into the given protocol instance.

        This method issues the 'LIST' FTP command.

        @param path: path to get a file listing for.
        @param protocol: a L{Protocol} instance, probably a
            L{FTPFileListProtocol} instance.  It can cope with most common file
            listing formats.

        @return: L{Deferred}
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/protocols/ftp.py