At the intersection of the Registry and Factory patterns lies the ClassRegistry:

  • Define global factories that generate new class instances based on configurable keys.
  • Seamlessly create powerful service registries.
  • Integrate with setuptools’s entry_points system to make your registries infinitely extensible by 3rd-party libraries!
  • And more!

Getting Started

Create a registry using the class_registry.ClassRegistry class, then decorate any classes that you wish to register with its register method:

from class_registry import ClassRegistry

pokedex = ClassRegistry()

class Charizard(Pokemon):

class Bulbasaur(Pokemon):

class Squirtle(Pokemon):

To create a class instance from a registry, use the subscript operator:

# Charizard, I choose you!
fighter1 = pokedex['fire']

# CHARIZARD fainted!
# How come my rival always picks the type that my pokémon is weak against??
fighter2 = pokedex['grass']

Advanced Usage

There’s a whole lot more you can do with ClassRegistry, including:

  • Provide args and kwargs to new class instances.
  • Automatically register non-abstract classes.
  • Integrate with setuptools’s entry_points system so that 3rd-party libraries can add their own classes to your registries.
  • Wrap your registry in an instance cache to create a service registry.
  • And more!

To learn more about what you can do with ClassRegistry, keep reading!


ClassRegistry is compatible with the following Python versions:

  • 3.8
  • 3.7
  • 3.6
  • 3.5

pypy3 is also supported.


ClassRegistry is not compatible with Python 2.


Install the latest stable version via pip:

pip install phx-class-registry