Example implementations of context managers

AsyncClassContextManager.py

import asyncio
from typing import Callable


class ScopedActions(object):
    startup: Callable[[], None]
    cleanup: Callable[[], None]
    name: str

    def __init__(self, name: str, startup: Callable[[], None], cleanup: Callable[[], None]):
        self.name = name
        self.startup = startup
        self.cleanup = cleanup

    async def __aenter__(self):
        await asyncio.sleep(1)
        self.startup()
        return self

    async def __aexit__(self, type, value, traceback):
        await asyncio.sleep(1)
        self.cleanup()


async def test():
    async with ScopedActions(name='test', startup=lambda: print('started'),
                             cleanup=lambda: print('finished')) as scoped:
        print('Executing:', scoped.name)


loop = asyncio.new_event_loop()
result = loop.run_until_complete(test())

AsyncGenaratorContextManager.py

import asyncio
from contextlib import asynccontextmanager
from typing import Callable


@asynccontextmanager
async def scoped_actions(name: str, startup: Callable[[], None], cleanup: Callable[[], None]):
    startup()
    await asyncio.sleep(1)
    yield name
    cleanup()


async def test():
    async with scoped_actions(name='test', startup=lambda: print('started'), cleanup=lambda: print('finished')) as name:
        print('Executing:', name)


loop = asyncio.new_event_loop()
result = loop.run_until_complete(test())

ClassContextManager.py

from typing import Callable


class ScopedActions(object):
    startup: Callable[[], None]
    cleanup: Callable[[], None]
    name: str

    def __init__(self, name: str, startup: Callable[[], None], cleanup: Callable[[], None]):
        self.name = name
        self.startup = startup
        self.cleanup = cleanup

    def __enter__(self):
        self.startup()
        return self

    def __exit__(self, type, value, traceback):
        self.cleanup()


with ScopedActions(name='test', startup=lambda: print('started'), cleanup=lambda: print('finished')) as scoped:
    print('Executing:', scoped.name)

GeneratorContextManager.py

from contextlib import contextmanager
from typing import Callable


@contextmanager
def scoped_actions(name: str, startup: Callable[[], None], cleanup: Callable[[], None]):
    startup()
    yield name
    cleanup()


with scoped_actions(name='test', startup=lambda: print('started'), cleanup=lambda: print('finished')) as name:
    print('Executing:', name)