[Philippe C. Martin] > I am looking into using the pickle format to store object/complex data > structures into a smart card as it would make the design of the embedded > application very simple. > > Yet the card might have to stay in the pocket of the customer for a few > years, during which the back office application responsible for > retrieving the information from the card might evolve as well as the > python release it relies upon. > > Is there a commitment for python releases to be able to interpret > 'older' pickle/marshal internal formats ?
Pickle and marshal have nothing in common, and there's no cross-release guarantee about marshal behavior. Pickles are safe in this respect; indeed, each Python released to date has been able to load pickles created by all earlier Python releases. Of course a pickle produced by a later Python may not be loadable by an earlier Python, although even in that direction you can get cross-release portability by forcing the newer Python to restrict itself to produce obsolete pickle formats. Reading Lib/pickletools.py in a current release will explain all this. -- http://mail.python.org/mailman/listinfo/python-list
