python-injection 0.2.1

Fast and easy dependency injection framework.

Injection

Fast and easy dependency injection framework.

Quick start

⚠️ Requires Python 3.10 or higher

pip install python-injection

How to use

Create an injectable

If you wish to inject a singleton, use unique decorator.

from injection import unique

@unique
class MyClass:
    """ class implementation """

If you wish to inject a new instance each time, use new decorator.

from injection import new

@new
class MyClass:
    """ class implementation """

Inject an instance

To inject one or several instances, use inject decorator. Don't forget to annotate type of parameter to inject.

from injection import inject

@inject
def my_function(instance: MyClass):
    """ function implementation """

Inheritance

In the case of inheritance, you can use the decorator parameters reference or references to link the injection to one or several other classes.

Warning: if the child class is in another file, make sure that file is imported before injection. See load_package function.

reference parameter example:

from injection import unique

class A:
    ...

@unique(reference=A)
class B(A):
    ...

references parameter example:

from injection import unique

class A:
    ...

class B(A):
    ...

@unique(references=(A, B))
class C(B):
    ...

Recipes

A recipe is a function that tells the injector how to construct the instance to be injected. It is important to specify the reference class(es) when defining the recipe.

from injection import unique

@unique(reference=MyClass)
def my_recipe() -> MyClass:
    """ recipe implementation """

Utils

load_package

Useful for put in memory injectables hidden deep within a package. Example:

package
├── sub_package
│   ├── __init__.py
│   └── module2.py
│       └── class Injectable2
├── __init__.py
└── module1.py
    └── class Injectable1

To load Injectable1 and Injectable2 into memory you can do the following:

from injection.utils import load_package

import package

load_package(package)