def __init__(self, rules='', **more_rules):
        decorated_custom_rules = dict(
            (k, expression(v, k, self) if isfunction(v) or
                                          ismethod(v) else
                v) for k, v in more_rules.iteritems())

        self._expressions, first = self._expressions_from_rules(rules, decorated_custom_rules)
        self.default_rule = first  # may be None
Construct a grammar.
dataset/ETHPy150Open erikrose/parsimonious/parsimonious/grammar.py/Grammar.__init__