Python并发执行的简易实现：多进程、多线程、协程

多进程

import logging
import time
from multiprocessing import Pool
logging.basicConfig(format='%(asctime)s %(message)s', level=logging.INFO)

def f(x):
    time.sleep(1)
    logging.info(x)
    return x


if __name__ == '__main__':
    with Pool(5) as p:
        p.map(f, [i for i in range(1, 100)])

多线程

import logging
import time
import threading
import queue

logging.basicConfig(format='%(asctime)s %(message)s', level=logging.INFO)

q = queue.Queue()


def worker():
    while True:
        item = q.get()
        time.sleep(1)
        logging.info(item)
        q.task_done()


# 启动线程数.
for i in range(3):
    threading.Thread(target=worker, daemon=True).start()


# Send thirty task requests to the worker.
for item in range(30):
    q.put(item)

# Block until all tasks are done.
q.join()
print('All work completed')

协程

import asyncio

def get_urls():
    return ['http://xxx.com', 'http://xxx.com']


async def get_title(url, sem):
    async with sem:
        time.sleep(2)
        print(url)


if __name__ == '__main__':
    loop = asyncio.get_event_loop()
    # 任务列表，列表里是coroutine或future
    tasks = []
    # 限制协程数量
    sem = asyncio.Semaphore(2)
    urls = get_urls()
    for url in urls:
        tasks.append(get_title(url, sem))
    try:
        loop.run_until_complete(asyncio.wait(tasks))
    finally:
        loop.close()

参考

​​多进程​​​​多线程​​​​协程​​