exar...@twistedmatrix.com wrote: > On 03:17 pm, pengyu...@gmail.com wrote: >> Hi, >> >> If I define my own class and use pickle to serialize the objects in >> this class, will the serialized object be successfully read in later >> version of python. >> >> What if I serialize (using pickle) an object of a class defined in >> python library, will it be successfully read in later version of >> python? > > Sometimes. Sometimes not. Python doesn't really offer any guarantees > regarding this.
I think this needs to be corrected: the pickle protocol versions are compatible between Python releases, however, there are two things to consider: * The default pickle version sometimes changes between minor releases. This is easy to handle, though, since you can provide the pickle protocol version as parameter. * The pickle protocol has changed a bit between 2.x and 3.x. This is mostly due to the fact that Python's native string format changed to Unicode in 3.x. http://docs.python.org/library/pickle.html#data-stream-for Finally, you can register your own pickle functions using the copy_reg module: http://docs.python.org/library/copy_reg.html OTOH, marshal, the more simplistic serialization format used for basic types and PYC files, does change often and is not guaranteed to be backwards compatible. -- Marc-Andre Lemburg eGenix.com Professional Python Services directly from the Source (#1, Oct 13 2009) >>> Python/Zope Consulting and Support ... http://www.egenix.com/ >>> mxODBC.Zope.Database.Adapter ... http://zope.egenix.com/ >>> mxODBC, mxDateTime, mxTextTools ... http://python.egenix.com/ ________________________________________________________________________ ::: Try our new mxODBC.Connect Python Database Interface for free ! :::: eGenix.com Software, Skills and Services GmbH Pastor-Loeh-Str.48 D-40764 Langenfeld, Germany. CEO Dipl.-Math. Marc-Andre Lemburg Registered at Amtsgericht Duesseldorf: HRB 46611 http://www.egenix.com/company/contact/ -- http://mail.python.org/mailman/listinfo/python-list
