#!/usr/bin/env python

# -*- coding: utf-8 -*-

class RegistryHolder(type):

REGISTRY = {}

def __new__(cls, name, bases, attrs):

new_cls = type.__new__(cls, name, bases, attrs)

"""

Here the name of the class is used as key but it could be any class

parameter.

"""

cls.REGISTRY[new_cls.__name__] = new_cls

return new_cls

@classmethod

def get_registry(cls):

return dict(cls.REGISTRY)

class BaseRegisteredClass(object):

"""

Any class that will inherits from BaseRegisteredClass will be included

inside the dict RegistryHolder.REGISTRY, the key being the name of the

class and the associated value, the class itself.

"""

__metaclass__ = RegistryHolder

def main():

"""

Before subclassing

>>> sorted(RegistryHolder.REGISTRY)

['BaseRegisteredClass']

>>> class ClassRegistree(BaseRegisteredClass):

... def __init__(self, *args, **kwargs):

... pass

After subclassing

>>> sorted(RegistryHolder.REGISTRY)

['BaseRegisteredClass', 'ClassRegistree']

"""

if __name__ == "__main__":

import doctest

doctest.testmod(optionflags=doctest.ELLIPSIS)