
``copyreg`` --- Register ``pickle`` support functions
*****************************************************

The ``copyreg`` module provides support for the ``pickle`` and
``cPickle`` modules.  The ``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.

copyreg.constructor(object)

   Declares *object* to be a valid constructor.  If *object* is not
   callable (and hence not valid as a constructor), raises
   ``TypeError``.

copyreg.pickle(type, function, constructor=None)

   Declares that *function* should be used as a "reduction" function
   for objects of type *type*.  *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.
   ``TypeError`` will be raised if *object* is a class or
   *constructor* is not callable.

   See the ``pickle`` module for more details on the interface
   expected of *function* and *constructor*.
