[issue6784] byte/unicode pickle incompatibilities between python2 and and python3

Martin v. Löwis added the comment: > how about a way to declare one wants exact 1:1 mapping between py2<>py3, > so str<>bytes and unicode<>str will work for sure In a sense, that's already possible. Inherit from _Pickler/_Unpickler, and replace the dispatch dict with a different mapping. I wou

[issue6784] byte/unicode pickle incompatibilities between python2 and and python3

RonnyPfannschmidt added the comment: in case the actual behavior is not supposed to change how about a way to declare one wants exact 1:1 mapping between py2<>py3, so str<>bytes and unicode<>str will work for sure something like load/dump(..., encoding=bytes) just crossed my mind --

[issue6784] byte/unicode pickle incompatibilities between python2 and and python3

RonnyPfannschmidt added the comment: unpickle of any non-ascii string from python2 will break the only way out would be to ensure text strings and a single defined encoding (at that point storing unicode strings in any case seems more practical) also byte-strings stored as python2 str would bre

[issue6784] byte/unicode pickle incompatibilities between python2 and and python3

Antoine Pitrou added the comment: The problem with trying to solve the following issue: "a bytes instance from python3 is pickled as custom class in protocols <3" is that if we pickle bytes from Python 3 as a 2.x str in protocol <= 2, unpickling it using Python 3 will yield a str (unicode), n

[issue6784] byte/unicode pickle incompatibilities between python2 and and python3

RonnyPfannschmidt added the comment: its even worse python3: >>> import pickle >>> pickle.dumps(b'', protocol=2) b'\x80\x02c__builtin__\nbytes\nq\x00]q\x01\x85q\x02Rq\x03.' python2.6: >>> import pickle >>> pickle.loads('\x80\x02c__builtin__\nbytes\nq\x00]q\x01\x85q\x02Rq\x03.') '[]' -

[issue6784] byte/unicode pickle incompatibilities between python2 and and python3

RonnyPfannschmidt added the comment: Since it breaks for anything non-ascii, its not that helpfull after all and since python2 strings are encoding-unaware there is no way to fix it. It might be preferable to supply unpicklers that are cappable of coercing if the user really wants wants coercin

[issue6784] byte/unicode pickle incompatibilities between python2 and and python3

Martin v. Löwis added the comment: > the basic behavior i want to see for all protocols <= 2 > > 1. python 2 string maps to python3 byte-string That would not be good. Many people create pickles in 2.x where the string type really represents characters, more often so than they want it to repre

[issue6784] byte/unicode pickle incompatibilities between python2 and and python3

RonnyPfannschmidt added the comment: the basic behavior i want to see for all protocols <= 2 1. python 2 string maps to python3 byte-string 2. python 2 unicode maps to python3 string 3. python 3 string map to python 2 unicode 4. python 3 bytestring maps to python 2 string anything else is is

[issue6784] byte/unicode pickle incompatibilities between python2 and and python3

Martin v. Löwis added the comment: Why are you reporting this here? If you think there is a bug, can you propose an alternative behavior that you would consider correct? The changes you mentioned are all deliberate. -- nosy: +loewis ___ Python track

[issue6784] byte/unicode pickle incompatibilities between python2 and and python3

Changes by RonnyPfannschmidt : -- title: bytw/unicode string incompatibilities between python2 and and python3 -> byte/unicode pickle incompatibilities between python2 and and python3 ___ Python tracker ___