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Python-dependency-injection is a simple yet powerful mini-framework for dependency injection in Python

Project description

python-dependency-injection

python-dependency-injection is a simple yet powerful mini-framework for dependency injection in Python

Installation

Use the package manager pip to install Python-dependency-injection.

pip install python-dependency-injection

Description

python-dependency-injection enable to easily inject any python class to another python
upon creation. It supports python 3.6 and above.

It is possible to inject the class as singleton (every injection will provide the same object instance)
or as singlecall (every injection will provide a diffrent object instance)

It is very easy to use all you need to do is put the autowired decorator on the __init__
function of the class you want to inject too (see below)

There are a few requirements of corse:
* You must use python typing hints in the injected __init__ - https://docs.python.org/3/library/typing.html
* The injected class cannot be python builtin types like str
* All injected classes should appear as the last parameters in the __init__ i.e. __init__(non_inject1, non_inject2, inject3: InjectType3, inject4 InjectType4)

If the framework can not inject an object a DependencyInjectionException will be raise specifing the error. 

Code

# this class will be injected
from dependency_injection.decorators.autowired import autowired
from dependency_injection.decorators.autowired_enums import AutoWiredType

class InjectedClass:
    def __init__(self):
        self.message: str = ' from InjectedClass'

    def foo(self, str1: str) -> str:
        return str1 + self.message


# class objects will be injected to
class TestSingletonInjection:
    @autowired()
    def __init__(self, my_name: str, injected_class: InjectedClass):
        self.injected_class = injected_class
        self.my_name = my_name

    def test_inject(self) -> str:
        return self.injected_class.foo('hello TestClassSingleton')


# class objects will be injected to
class TestSingleCallInjection:
    @autowired(AutoWiredType.SINGLECALL)
    def __init__(self, my_name: str, injected_class: InjectedClass):
        self.injected_class = injected_class
        self.my_name = my_name

    def test_inject(self) -> str:
        return self.injected_class.foo('hello TestClassSinglecall')

if __name__ == '__main__':
    test_singleton_injection: TestSingletonInjection = TestSingletonInjection('TestSingletonInjection')
    print(test_singleton_injection.test_inject())

    test_singlecall_injection: TestSingleCallInjection = TestSingleCallInjection('TestSingleCallInjection')
    print(test_singlecall_injection.test_inject())

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change. Please make sure to update tests as appropriate.

##License MIT

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