> One thing that annoyed me about both Python and Rubyis that the way things in the standard library worked changed from release to release in subtle, incompati

> One thing that annoyed me about both Python and Rubyis that the way things in the standard library worked changed from release to release in subtle, incompatible ways. I got bitten by one such implementation detail changing in between releases in python. It had something to do with the pickle machinery, like the 'set' builtin changing from using __reduce__ to __reduce_ex__ or vice versa, or something like that, and all the pickles that were serialized in 2.4 were deserializing incorrectly in 2.6. I can't remember the details now :\