Dependency injection made for python
- Easy to use interface
- Extensible with custom dependency resolvers
- Automatic dependency injection
- Lightweight
- Support for async with asyncio
pip install kink
Dependency container is a dict-like object, adding new service to dependency container is as simple as the following example:
from kink import di
from os import getenv
di["db_name"] = getenv("DB_NAME")
di["db_password"] = getenv("DB_PASSWORD")Kink also supports on-demand service creation. In order to define such a service, lambda function should be used:
from kink import di
from sqlite3 import connect
di["db_connection"] = lambda di: connect(di["db_name"])In this scenario connection to database will not be established until service is requested.
from kink import di
from sqlite3 import connect
# Setting services
di["db_name"] = "test_db.db"
di["db_connection"] = lambda di: connect(di["db_name"])
# Getting service
connection = di["db_connection"] # will return instance of sqlite3.Connection
assert connection == di["db_connection"] # Truefrom kink import di, inject
from sqlite3 import connect, Connection
di["db_name"] = "test_db.db"
di["db_connection"] = lambda di: connect(di["db_name"])
# Inject connection from di, connection is established once function is called.
@inject
def get_database(db_connection: Connection):
...
connection = get_database()
connection_with_passed_connection = get_database(connect("temp.db")) # will use passed connectionfrom kink import inject, di
import MySQLdb
# Set dependencies
di["db_host"] = "localhost"
di["db_name"] = "test"
di["db_user"] = "user"
di["db_password"] = "password"
di["db_connection"] = lambda di: MySQLdb.connect(host=di["db_host"], user=di["db_user"], passwd=di["db_password"], db=di["db_name"])
@inject
class AbstractRepository:
def __init__(self, db_connection):
self.connection = db_connection
class UserRepository(AbstractRepository):
...
repository = UserRepository()
repository.connection # mysql db connection is resolved and available to use.When class is annotated by inject annotation it will be automatically added to the container for future use (eg autowiring).
When you registering service with @inject decorator you can attach your own alias name, please consider the following example:
from kink import inject
from typing import Protocol
class IUserRepository(Protocol):
...
@inject(alias=IUserRepository)
class UserRepository:
...
assert di[IUserRepository] == di[UserRepository] # returns trueFor more examples check tests directory