Factory

The Factory pattern provides a centralized registry for dynamically creating objects by name.

It allows you to register classes (or any callable) and instantiate them using a string identifier. This pattern is useful in plugin systems, strategy selectors, configuration-driven object creation, and more.

Overview

The factory maintains a registry of constructors (classes or callables). Once registered under a key, the object can be created with optional keyword arguments.

You can also use the @register_factory(“name”) decorator to register classes automatically.

Example Usage

from pattern_kit import Factory

class Car:
    def __init__(self, color):
        self.color = color

class Truck:
    def __init__(self, capacity):
        self.capacity = capacity

Factory.register("car", Car)
Factory.register("truck", Truck)

car = Factory.create("car", color="blue")
truck = Factory.create("truck", capacity=5000)

print(type(car), car.color)
print(type(truck), truck.capacity)

Decorator Usage

from pattern_kit import register_factory, Factory

@register_factory("car")
class Car:
    def __init__(self, color):
        self.color = color

log = Factory.create("car", color="blue")

API Reference

class pattern_kit.creational.factory.Factory[source]

Bases: object

A simple, extensible Factory pattern implementation.

Allows registering classes or callables by name, then instantiating them via .create(“name”, **kwargs).

classmethod clear() → None[source]: Clear all registered factories.

classmethod create(key: str, *args, **kwargs) → Any[source]: Create an instance of the registered class or factory function.

classmethod register(key: str, constructor: Type) → None[source]: Register a class or callable under a name.

classmethod unregister(key: str) → None[source]: Remove a registered factory.

pattern_kit.creational.factory.register_factory(key: str)[source]: Decorator that registers a class or callable into the Factory registry.