Python中协程间通信的方式小结

import asyncio

async def producer(queue):
    for i in range(5):
        await queue.put(i)
        print(f"Produced: {i}")
        await asyncio.sleep(1)

async def consumer(queue):
    while True:
        item = await queue.get()
        if item is None:  # 用 None 表示终止信号
            break
        print(f"Consumed: {item}")
        await asyncio.sleep(2)

async def main():
    queue = asyncio.Queue()
    await asyncio.gather(producer(queue), consumer(queue))

asyncio.run(main())

import asyncio

async def waiter(event):
    print("Waiting for event...")
    await event.wait()  # 阻塞直到事件被触发
    print("Event occurred!")

async def setter(event):
    await asyncio.sleep(2)
    print("Setting event!")
    event.set()  # 设置事件

async def main():
    event = asyncio.Event()
    await asyncio.gather(waiter(event), setter(event))

asyncio.run(main())

import asyncio

async def consumer(condition, shared_data):
    async with condition:
        while shared_data["item"] is None:
            await condition.wait()  # 等待条件
        print(f"Consumed: {shared_data['item']}")
        shared_data["item"] = None

async def producer(condition, shared_data):
    await asyncio.sleep(1)
    async with condition:
        shared_data["item"] = "Apple"
        condition.notify()  # 通知等待的协程
        print(f"Produced: {shared_data['item']}")

async def main():
    shared_data = {"item": None}
    condition = asyncio.Condition()
    await asyncio.gather(producer(condition, shared_data), consumer(condition, shared_data))

asyncio.run(main())

import asyncio

async def task(sem):
    async with sem:
        print("Task started")
        await asyncio.sleep(1)
        print("Task completed")

async def main():
    sem = asyncio.Semaphore(2)  # 最多同时运行2个协程
    tasks = [task(sem) for _ in range(5)]
    await asyncio.gather(*tasks)

asyncio.run(main())

import asyncio

async def echo(reader, writer):
    data = await reader.read(100)
    message = data.decode()
    addr = writer.get_extra_info('peername')
    print(f"Received {message} from {addr}")

    print("Send: %r" % message)
    writer.write(data)
    await writer.drain()

    print("Closing the connection")
    writer.close()

async def main():
    server = await asyncio.start_server(
        echo, '127.0.0.1', 8888)

    addr = server.sockets[0].getsockname()
    print(f'Serving on {addr}')

    async with server:
        await server.serve_forever()

asyncio.run(main())

import asyncio

async def set_future(future):
    await asyncio.sleep(1)
    future.set_result('Hello from Future!')

async def get_future(future):
    result = await future
    print(f"Got result: {result}")

async def main():
    future = asyncio.Future()
    await asyncio.gather(set_future(future), get_future(future))

asyncio.run(main())