import random def _dependency_injection(): from abc import ABC, abstractmethod class DataBaseAbstract(ABC): @abstractmethod def connect(self): pass class SQLite(DataBaseAbstract): def connect(self): print('SQLite: connection with sqlite is completed') class MySQL(DataBaseAbstract): def connect(self): print('MySQL: connection with sqlite is completed') class DataBase: def __init__(self, db: DataBaseAbstract): self.db: DataBaseAbstract = db def get_column(self): self.db.connect() db_sqlite: DataBase = DataBase(SQLite()) db_sqlite.get_column() db_mysql: DataBase = DataBase(MySQL()) db_mysql.get_column() def _dependency_injector(): from dependency_injector import containers, providers class Sensor: def __init__(self, ip, id): self.ip = ip self.id = id class Server: def __init__(self, clients: [Sensor]): self.clients: [Sensor] = clients class Container(containers.DeclarativeContainer): config = providers.Configuration() server = providers.Singleton( Server, clients=config.clients ) sensor = providers.Factory( Sensor, ip=config.ip, id=config.id ) container = Container() server = container.server() server.clients = [Sensor('127.0.0.1', random.randint(1, 100)) for _ in range(10)] print(server.clients) print(server.clients[0].ip) if __name__ == '__main__': _dependency_injection() _dependency_injector()