Quickstart

1. Install dishka

pip install dishka

2. Create Provider instance. It is only used to setup all factories providing your objects.

from dishka import Provider

provider = Provider()

3. Register functions which provide dependencies. Do not forget to place correct typehints for parameters and result. We use scope=Scope.APP for dependencies which ar created only once in application lifetime, and scope=Scope.REQUEST for those which should be recreated for each processing request/event/etc.

from dishka import Provider, Scope

def get_a() -> A:
    return A()

def get_b(a: A) -> B:
    return B(a)

provider = Provider()
provider.provide(get_a, scope=Scope.APP)
provider.provide(get_b, scope=Scope.REQUEST)

This can be also rewritten using class:

from dishka import provide, Provider, Scope

class MyProvider(Provider):
   @provide(scope=Scope.APP)
   def get_a(self) -> A:
      return A()

   @provide(scope=Scope.REQUEST)
   def get_b(self, a: A) -> B:
      return B(a)

provider = MyProvider()

4. Create Container instance passing providers, and step into APP scope. Container holds dependencies cache and is used to retrieve them. Here, you can use .get method to access APP-scoped dependencies:

from dishka import make_container

container = make_container(provider)  # it has Scope.APP
a = container.get(A)  # `A` has Scope.APP, so it is accessible here

5. You can enter and exit REQUEST scope multiple times after that using context manager:

from dishka import make_container

container = make_container(provider)
with container() as request_container:
    b = request_container.get(B)  # `B` has Scope.REQUEST
    a = request_container.get(A)  # `A` is accessible here too

with container() as request_container:
    b = request_container.get(B)  # another instance of `B`
    a = request_container.get(A)  # the same instance of `A`

6. Close container in the end:

container.close()

6. If you are using supported framework add decorators and middleware for it.

from dishka.integrations.fastapi import (
    FromDishka, inject, setup_dishka,
)

@router.get("/")
@inject
async def index(a: FromDishka[A]) -> str:
    ...

...
setup_dishka(container, app)