def relative_filename(self, filename):
fnorm = os.path.normcase(filename)<EOL>if fnorm.startswith(self.relative_dir):<EOL><INDENT>filename = filename[len(self.relative_dir):]<EOL><DEDENT>return filename<EOL>
Return the relative form of `filename`.

        The filename will be relative to the current directory when the
        `FileLocator` was constructed.