Berker Peksag added the comment: https://docs.python.org/2/library/pickle.html#object.__getinitargs__ states: "If it is desirable that the __init__() method be called on unpickling, an old-style class can define a method __getinitargs__(), which should return a tuple containing the arguments to be passed to the class constructor (__init__() for example)." However, there is no mention that it only accepts positional arguments. This is a Python 2-only change and the documentation file is located at Doc/library/pickle.rst in 2.7 branch. ---------- keywords: +easy nosy: +berker.peksag stage: -> needs patch _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue22392> _______________________________________