copyreg.pickle()

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. Note that the dispatch_table attribute of a pickler object or subclass of pickle.Pickler can also be used for declaring reduction functions.