pickletester.py 文件源码

def check_frame_opcodes(self, pickled):
        """
        Check the arguments of FRAME opcodes in a protocol 4+ pickle.
        """
        frame_opcode_size = 9
        last_arg = last_pos = None
        for op, arg, pos in pickletools.genops(pickled):
            if op.name != 'FRAME':
                continue
            if last_pos is not None:
                # The previous frame's size should be equal to the number
                # of bytes up to the current frame.
                frame_size = pos - last_pos - frame_opcode_size
                self.assertEqual(frame_size, last_arg)
            last_arg, last_pos = arg, pos
        # The last frame's size should be equal to the number of bytes up
        # to the pickle's end.
        frame_size = len(pickled) - last_pos - frame_opcode_size
        self.assertEqual(frame_size, last_arg)