#!/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(metaclass=RegistryHolder):

"""

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.

"""

pass

if __name__ == "__main__":

print("Before subclassing: ")

for k in RegistryHolder.REGISTRY:

print(k)

class ClassRegistree(BaseRegisteredClass):

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

pass

print("After subclassing: ")

for k in RegistryHolder.REGISTRY:

print(k)

### OUTPUT ###

# Before subclassing:

# BaseRegisteredClass

# After subclassing:

# BaseRegisteredClass

# ClassRegistree