def __init__(self, settings={}):
        CodePrinter.__init__(self, settings)
        self.known_functions = dict(known_functions)
        userfuncs = settings.get('user_functions', {})
        self.known_functions.update(userfuncs)
        # leading columns depend on fixed or free format
        if self._settings['source_format'] == 'fixed':
            self._lead_code = "      "
            self._lead_cont = "     @ "
            self._lead_comment = "C     "
        elif self._settings['source_format'] == 'free':
            self._lead_code = ""
            self._lead_cont = "      "
            self._lead_comment = "! "
        else:
            raise ValueError("Unknown source format: %s" % self._settings[
                             'source_format'])
        standards = {66, 77, 90, 95, 2003, 2008}
        if self._settings['standard'] not in standards:
            raise ValueError("Unknown Fortran standard: %s" % self._settings[
                             'standard'])
dataset/ETHPy150Open sympy/sympy/sympy/printing/fcode.py/FCodePrinter.__init__/original