def from_file(cls, filename):
        """
        Read an Fiesta input from a file. Currently tested to work with
        files generated from this class itself.

        Args:
            filename: Filename to parse.

        Returns:
            FiestaInput object
        """
        with zopen(filename) as f:
            return cls.from_string(f.read())
Read an Fiesta input from a file. Currently tested to work with
        files generated from this class itself.

        Args:
            filename: Filename to parse.

        Returns:
            FiestaInput object