pickletools.py 文件源码

def _genops(data, yield_end_pos=False):
    if isinstance(data, bytes_types):
        data = io.BytesIO(data)

    if hasattr(data, "tell"):
        getpos = data.tell
    else:
        getpos = lambda: None

    while True:
        pos = getpos()
        code = data.read(1)
        opcode = code2op.get(code.decode("latin-1"))
        if opcode is None:
            if code == b"":
                raise ValueError("pickle exhausted before seeing STOP")
            else:
                raise ValueError("at position %s, opcode %r unknown" % (
                                 "<unknown>" if pos is None else pos,
                                 code))
        if opcode.arg is None:
            arg = None
        else:
            arg = opcode.arg.reader(data)
        if yield_end_pos:
            yield opcode, arg, pos, getpos()
        else:
            yield opcode, arg, pos
        if code == b'.':
            assert opcode.name == 'STOP'
            break