ClassRegistry

Contents:

ClassRegistry

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()

@pokedex.register('fire')
class Charizard(Pokemon):
  ...

@pokedex.register('grass')
class Bulbasaur(Pokemon):
  ...

@pokedex.register('water')
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!

Requirements

ClassRegistry is known to be compatible with the following Python versions:

  • 3.12

  • 3.11

  • 3.10

Note

I’m only one person, so to keep from getting overwhelmed, I’m only committing to supporting the 3 most recent versions of Python. ClassRegistry’s code is pretty simple, so it’s likely to be compatible with versions not listed here; there just won’t be any test coverage to prove it 😇

Installation

Install the latest stable version via pip:

pip install phx-class-registry

Important

Make sure to install phx-class-registry, not class-registry. I created the latter at a previous job years ago, and after I left they never touched that project again — so in the end I had to fork it 🤷