Skip to main content

Factory+Registry pattern for Python classes.

Project description


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 klass_registry.ClassRegistry class, then decorate any classes that you wish to register with its register method:

from klass_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!

For more advanced usage, check out the documentation on ReadTheDocs!


ClassRegistry is compatible with Python versions 3.7, 3.6, 3.5 and 2.7.


Install the latest stable version via pip:

pip install klass-registry

Running Unit Tests

To run unit tests after installing from source:

python test

This project is also compatible with tox, which will run the unit tests in different virtual environments (one for each supported version of Python).

To run the unit tests, it is recommended that you use the detox library. detox speeds up the tests by running them in parallel.

Install the package with the test-runner extra to set up the necessary dependencies, and then you can run the tests with the tox command:

pip install -e .[test-runner]
tox -v


Documentation is available on ReadTheDocs.

If you are installing from source (see above), you can also build the documentation locally:

  1. Install extra dependencies (you only have to do this once):

    pip install '.[docs-builder]'
  2. Switch to the docs directory:

    cd docs
  3. Build the documentation:

    make html

Project details

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

klass-registry-2.2.2.tar.gz (16.4 kB view hashes)

Uploaded source

Built Distribution

klass_registry-2.2.2-py2.py3-none-any.whl (12.3 kB view hashes)

Uploaded py2 py3

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page