@classmethod
    def evaluate(cls, nodelist):
        while len(nodelist)==2: nodelist = nodelist[1]
        kind = nodelist[0]
        name = nodelist[1]
        if kind==token.NAME:
            try:
                op = cls.values[name]
            except __HOLE__:
                raise SyntaxError("Unknown name %r" % name)
            return op()
        if kind==token.STRING:
            s = nodelist[1]
            if not cls._safe_string(s):
                raise SyntaxError(
                    "Only plain strings allowed in environment markers")
            return s[1:-1]
        msg = "Language feature not supported in environment markers"
        raise SyntaxError(msg)
dataset/ETHPy150Open anzev/hedwig/build/pip/pip/_vendor/pkg_resources/__init__.py/MarkerEvaluation.evaluate