cpython/Doc/library/copyreg.rst

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:mod:`copyreg` --- Register :mod:`pickle` support functions
===========================================================
.. module:: copy_reg
:synopsis: Old name for the copyreg module.
.. module:: copyreg
:synopsis: Register pickle support functions.
.. note::
The :mod:`copy_reg` module has been renamed to :mod:`copyreg` in Python 3.0.
It is importable under both names in Python 2.6 and the rest of the 2.x
series.
.. index::
module: pickle
module: cPickle
module: copy
The :mod:`copyreg` 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*.