parser.py 文件源码

def parse_grouped_expr(self):
        self.next()

        if self.cur_is(token.RPAREN):
            expr = ast.Tuple(self.cur_tok, [])

            return expr

        expr = self.parse_expr(LOWEST)

        if self.peek_is(token.COMMA):
            self.next()
            self.next()

            expr = ast.Tuple(expr.token, [expr] + self.parse_expr_list(token.RPAREN))

        if type(expr) != ast.Tuple and not self.expect(token.RPAREN):
            return None

        return expr