A Container for the Dependency Injection in Python

Python Dependency Injection library

aiodi is a Container for the Dependency Injection in Python.

Installation

Use the package manager pip to install aiodi.

pip install aiodi

Documentation

Visit aiodi docs.

Usage

from abc import ABC, abstractmethod
from logging import Logger, getLogger, NOTSET, StreamHandler, Formatter
from os import getenv

from aiodi import Container
from typing import Optional, Union

_CONTAINER: Optional[Container] = None


def get_simple_logger(
        name: Optional[str] = None,
        level: Union[str, int] = NOTSET,
        fmt: str = '[%(asctime)s] - %(name)s - %(levelname)s - %(message)s',
) -> Logger:
    logger = getLogger(name)
    logger.setLevel(level)
    handler = StreamHandler()
    handler.setLevel(level)
    formatter = Formatter(fmt)
    handler.setFormatter(formatter)
    logger.addHandler(handler)
    return logger


class GreetTo(ABC):
    @abstractmethod
    def __call__(self, who: str) -> None:
        pass


class GreetToWithPrint(GreetTo):
    def __call__(self, who: str) -> None:
        print('Hello ' + who)


class GreetToWithLogger(GreetTo):
    _logger: Logger

    def __init__(self, logger: Logger) -> None:
        self._logger = logger

    def __call__(self, who: str) -> None:
        self._logger.info('Hello ' + who)


def container() -> Container:
    global _CONTAINER
    if _CONTAINER:
        return _CONTAINER
    di = Container({'env': {
        'name': getenv('APP_NAME', 'aiodi'),
        'log_level': getenv('APP_LEVEL', 'INFO'),
    }})
    di.resolve([
        (
            Logger,
            get_simple_logger,
            {
                'name': di.resolve_parameter(lambda di_: di_.get('env.name', typ=str)),
                'level': di.resolve_parameter(lambda di_: di_.get('env.log_level', typ=str)),
            },
        ),
        (GreetTo, GreetToWithLogger),  # -> (GreetTo, GreetToWithLogger, {})
        GreetToWithPrint,  # -> (GreetToWithPrint, GreetToWithPrint, {})
    ])
    di.set('who', 'World!')
    # ...
    _CONTAINER = di
    return di


def main() -> None:
    di = container()

    di.get(Logger).info('Just simple call get with the type')

    for greet_to in di.get(GreetTo, instance_of=True):
        greet_to(di.get('who'))


if __name__ == '__main__':
    main()