parser.py 文件源码

def parse_subscript(self, node):
        token = next(self.stream)
        if token.type == 'dot':
            attr_token = self.stream.current
            next(self.stream)
            if attr_token.type == 'name':
                return nodes.Getattr(node, attr_token.value, 'load',
                                     lineno=token.lineno)
            elif attr_token.type != 'integer':
                self.fail('expected name or number', attr_token.lineno)
            arg = nodes.Const(attr_token.value, lineno=attr_token.lineno)
            return nodes.Getitem(node, arg, 'load', lineno=token.lineno)
        if token.type == 'lbracket':
            args = []
            while self.stream.current.type != 'rbracket':
                if args:
                    self.stream.expect('comma')
                args.append(self.parse_subscribed())
            self.stream.expect('rbracket')
            if len(args) == 1:
                arg = args[0]
            else:
                arg = nodes.Tuple(args, 'load', lineno=token.lineno)
            return nodes.Getitem(node, arg, 'load', lineno=token.lineno)
        self.fail('expected subscript expression', self.lineno)