Dependency Injection Container Micro-framework for implementing IoC
Dependency Injection Container for Python 3+ influenced partially by Autofac. dic aims to be a tiny framework to help you manage dependencies.
dic uses Python 3 annotations to provide hints for the components that should be injected.
- dic is available via pip:
pip install dic
Currently, dic supports:
- Constructor injection for classes
- Factory and Lazy relationships
- Registration via:
- Constructor matching for a registered class
- Custom callback
- Lifetime scopes:
- Instance per dependency
- Single instance
- A quick example on how to use dic:
import dic class SimpleThing(object): def say(self, message): print(message) class RequiresThing(object): def __init__(self, thing: SimpleThing): self.thing = thing def say(self, message): self.thing.say(message) # build the container builder = dic.container.ContainerBuilder() builder.register_class(SimpleThing) builder.register_class(RequiresThing, component_scope=dic.scope.SingleInstance) container = builder.build() # use the container # Note there'll only be one of these due to SingleInstance scoping during build x = container.resolve(RequiresThing) x.say("my message")
dic supports basic relationships:
- dic.rel.Lazy - don’t create the dependency until it’s first used
- dic.rel.Factory - the component wants to create other components. Lifetime scopes are respected. Supports custom arguments.
- Using a factory:
import dic class SimpleThing(object): def __init__(self, special_argument): self.special_argument = special_argument class BuildsThings(object): def __init__(self, thing_factory: dic.rel.Factory(SimpleThing)): self.thing_factory = thing_factory def build_me_a_thing(self): # builds a new thing using the injected factory # Note that custom arguments can be provided here self.thing_factory(special_argument="My super special argument") # build the container builder = dic.container.ContainerBuilder() builder.register_class(SimpleThing) builder.register_class(BuildsThing) container = builder.build() # use the container x = container.resolve(BuildsThing) # use it thing = x.build_me_a_thing() # ...
- Is dic thread-safe?
Not yet. There’s plans to make it thread-safe.
- Can I define my own scopes?
Yes. Derive a scope from dic.scope.Scope. Scopes can be used to provide lifetime for a calling thread, for example
- Will you support feature “X”?
The philosophy of dic is to remain small, but extensible – e.g. remain “out of the way.” So likely not.