:mod:`copy_reg` --- Register :mod:`pickle` support functions

============================================================

.. module:: copy_reg

   :synopsis: Register pickle support functions.

.. note::

   The :mod:`copy_reg` module has been renamed to :mod:`copyreg` in Python 3.0.

   The :term:`2to3` tool will automatically adapt imports when converting your

   sources to 3.0.

.. index::

   module: pickle

   module: cPickle

   module: copy

The :mod:`copy_reg` module provides support for the :mod:`pickle` and

:mod:`cPickle` modules.  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.  Such constructors may be factory functions or class

instances.

.. function:: constructor(object)

   Declares *object* to be a valid constructor.  If *object* is not callable (and

   hence not valid as a constructor), raises :exc:`TypeError`.

.. function:: pickle(type, function[, constructor])

   Declares that *function* should be used as a "reduction" function for objects of

   type *type*; *type* must not be a "classic" class object.  (Classic classes are

   handled differently; see the documentation for the :mod:`pickle` module for

   details.)  *function* should return either a string or a tuple containing two or

   three elements.

   The optional *constructor* parameter, if provided, is a callable object which

   can be used to reconstruct the object when called with the tuple of arguments

   returned by *function* at pickling time.  :exc:`TypeError` will be raised if

   *object* is a class or *constructor* is not callable.

   See the :mod:`pickle` module for more details on the interface expected of

   *function* and *constructor*.