autoinject 0.1.0

Automated dependency injection for Python

Autoinject

A clean, simple framework for automatically injecting dependencies into objects and functions based around Python's type-hinting system. The framework provides caching of injectable objects, though this may be disabled on a class-by-class basis. It also supports managing independent caches for different contexts.

Define Injectable Classes

# Easy mode

from autoinject import injector

@injector.injectable
class MyInjectableClass:

    # __init__() should have no additional required arguments
    def __init__(self):
        pass


# Hard mode, must specify the fully-qualified name of the class,
# but gain control over the arguments

@injector.register("example.MyInjectableClass", os.environ("MY_CONFIG_FILE"))
class MyInjectableClass:

    def __init__(self, config_file):
        # we receive os.environ("MY_CONFIG_FILE") as config_file here
        # positional and keyword arguments to @injector.register() are supported
        pass

Inject Objects With Decorators

# Decorate with @injector.inject for functions/methods:

@injector.inject
def inject_me(param1, param2, injected_param: MyInjectableClass):
    # injected_param is set to an instance of MyInjectableClass
    pass

# Omit the injected parameters when calling it:

inject_me("arg1", "arg2")


# For classes, use @injector.construct to set instance attributes 
# based on the class attributes   
class InjectMe:

    injected_attribute: MyInjectableClass = None

    @injector.construct
    def __init__(self):
        # self.injected_attribute is set to an instance of MyInjectableClass
        pass

# No need to do anything special here:
obj = InjectMe()
# obj.injected_attribute is set by the decorator before __init__() is called.

Read the full documentation for more details.