python 协程

标签：star   time   pre   app   __name__   并行   end   started   for   

import asyncio
import time


async def say_after(delay, what):
    """使用 async 声明函数"""
    await asyncio.sleep(delay)
    print(what)


async def main():
    # 一个一个执行
    print(f"started at {time.strftime(‘%X‘)}")
    await say_after(1, ‘hello‘)
    await say_after(2, ‘world‘)
    print(f"started at {time.strftime(‘%X‘)}")

    # 并行执行 1. 先创建在执行
    task1 = asyncio.create_task(say_after(1, ‘hello‘))
    task2 = asyncio.create_task(say_after(2, ‘world‘))
    print(f"started at {time.strftime(‘%X‘)}")
    await task1
    await task2
    print(f"finished at {time.strftime(‘%X‘)}")

    # 并行并行 2. 直接运行,使用 asyncio.gather方法
    await asyncio.gather(
        say_after(2, "A"),
        say_after(3, "B"),
        say_after(4, "C"),
    )

    # 并发运行 task 任务
    urls = ["http://ww.cn", "http://ww.cn", "http://ww.cn", "http://ww.cn"]
    task = []
    for i in urls:
        task.append(asyncio.create_task(say_after(i, i)))
    await asyncio.wait(
        task
    )


if __name__ == ‘__main__‘:
    # 创建协程对象
    asyncio.run(main())

python 协程

标签：star   time   pre   app   __name__   并行   end   started   for   

原文地址：https://www.cnblogs.com/namejmj/p/14747488.html