Python v3 question related to pickle/marshal

[Detlev Offenbach]

Hi,

is it possible to marshal or pickle a data structure using Python v3 and
unmarshal or unpickle it using Python v2. If it is possible, how do I
have to do it. Everything I tried resulted in an EOFError exception upon
unmarshalling/unpickling.

Regards,
Detlev

 

[Tino Wildenhain]

Hi,

is it possible to marshal or pickle a data structure using Python v3 and
unmarshal or unpickle it using Python v2. If it is possible, how do I
have to do it. Everything I tried resulted in an EOFError exception upon
unmarshalling/unpickling.

Could you give the code of a minimal example how you tried?

Regards
Tino

PS: it would not hurt to end questions with a question mark ;-)

 

[Peter Otten]

is it possible to marshal or pickle a data structure using Python v3 and
unmarshal or unpickle it using Python v2. If it is possible, how do I
have to do it. Everything I tried resulted in an EOFError exception upon
unmarshalling/unpickling.

It seems to work here, at least for simple data:

$ python3.0
Python 3.0 (r30:67503, Dec 4 2008, 11:26:28)
[GCC 4.1.3 20070929 (prerelease) (Ubuntu 4.1.2-16ubuntu2)] on linux2
Type "help", "copyright", "credits" or "license" for more information.

import pickle
pickle.dump(dict(a=1, b=[42], c="yadda"), open("tmp.p", "wb"), protocol=2)

$ python
Python 2.5.1 (r251:54863, Jul 31 2008, 23:17:43)
[GCC 4.1.3 20070929 (prerelease) (Ubuntu 4.1.2-16ubuntu2)] on linux2
Type "help", "copyright", "credits" or "license" for more information.{u'a': 1, u'c': u'yadda', u'b': [42]}

Maybe you have incompatible data structures?

Peter

 

[Detlev Offenbach]

Could you give the code of a minimal example how you tried?

The problem is fixed. The bug was somewhere else making me believe the
pickled file couldn't be read.