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

     2 ============================================================

     3 

     4 .. module:: copy_reg

     5    :synopsis: Register pickle support functions.

     6 

     7 .. note::

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

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

    10    sources to 3.0.

    11 

    12 .. index::

    13    module: pickle

    14    module: cPickle

    15    module: copy

    16 

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

    18 :mod:`cPickle` modules.  The :mod:`copy` module is likely to use this in the

    19 future as well.  It provides configuration information about object constructors

    20 which are not classes.  Such constructors may be factory functions or class

    21 instances.

    22 

    23 

    24 .. function:: constructor(object)

    25 

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

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

    28 

    29 

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

    31 

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

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

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

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

    36    three elements.

    37 

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

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

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

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

    42 

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

    44    *function* and *constructor*.

    45