diff options
| -rw-r--r-- | Doc/library/copy.rst | 4 | ||||
| -rw-r--r-- | Doc/library/copyreg.rst | 29 |
2 files changed, 28 insertions, 5 deletions
diff --git a/Doc/library/copy.rst b/Doc/library/copy.rst index 0c68bd9..1db5c2d 100644 --- a/Doc/library/copy.rst +++ b/Doc/library/copy.rst @@ -67,8 +67,8 @@ of lists by assigning a slice of the entire list, for example, 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 index 41061e5..50d5879 100644 --- a/Doc/library/copyreg.rst +++ b/Doc/library/copyreg.rst @@ -9,9 +9,10 @@ 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 -configuration information about object constructors which are not classes. +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. The module provides configuration +information about object constructors which are not classes. Such constructors may be factory functions or class instances. @@ -37,3 +38,25 @@ Such constructors may be factory functions or class instances. :attr:`~pickle.Pickler.dispatch_table` attribute of a pickler object or subclass of :class:`pickle.Pickler` can also be used for declaring reduction functions. + +Example +------- + +The example below would like to show how to register a pickle function and how +it will be used: + + >>> import copyreg, copy, pickle + >>> 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... |