diff --git a/Doc/library/copy.rst b/Doc/library/copy.rst --- a/Doc/library/copy.rst +++ b/Doc/library/copy.rst @@ -63,8 +63,8 @@ Classes can use the same interfaces to control copying that they use to control pickling. See the description of module :mod:`pickle` for information on these -methods. The :mod:`copy` module does not use the :mod:`copyreg` registration -module. +methods. In fact, :mod:`copy` module uses the registered pickle functions from +:mod:`copyreg` module. .. index:: single: __copy__() (copy protocol) diff --git a/Doc/library/copyreg.rst b/Doc/library/copyreg.rst --- a/Doc/library/copyreg.rst +++ b/Doc/library/copyreg.rst @@ -9,8 +9,9 @@ module: pickle module: copy -The :mod:`copyreg` module provides support for the :mod:`pickle` module. The -:mod:`copy` module is likely to use this in the future as well. It provides +The :mod:`copyreg` module offers a way to define fuctions used while pickling +specific objects. The :mod:`pickle` and :mod:`copy` modules use those functions +when pickling/copying those objects. It provides configuration information about object constructors which are not classes. Such constructors may be factory functions or class instances. @@ -35,3 +36,24 @@ See the :mod:`pickle` module for more details on the interface expected of *function* and *constructor*. + +Example +------- + +The example below would like to show how to register a pickle function and how +it will be used: + + >>> class C(object): + ... def __init__(self, a): + ... self.a = a + ... + >>> def pickle_c(c): + ... print("pickling a C instance...") + ... return C, (c.a,) + ... + >>> copyreg.pickle(C, pickle_c) + >>> c = C(1) + >>> d = copy.copy(c) + pickling a C instance... + >>> p = pickle.dumps(c) + pickling a C instance...