cpython/Doc/library/copyreg.rst

40 lines
1.5 KiB
ReStructuredText
Raw Normal View History

:mod:`copyreg` --- Register :mod:`pickle` support functions
===========================================================
2007-08-15 11:28:22 -03:00
.. module:: copyreg
2007-08-15 11:28:22 -03:00
:synopsis: Register pickle support functions.
.. index::
module: pickle
module: copy
2009-12-13 17:04:16 -04:00
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.
Such constructors may be factory functions or class instances.
2007-08-15 11:28:22 -03:00
.. 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=None)
2007-08-15 11:28:22 -03:00
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.
2007-08-15 11:28:22 -03:00
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*. Note that the
:attr:`~pickle.Pickler.dispatch_table` attribute of a pickler
object or subclass of :class:`pickle.Pickler` can also be used for
declaring reduction functions.