Python并发编程

from concurrent.futures import ThreadPoolExecutor, ProcessPoolExecutor# 使用线程池（默认线程数为 CPU 核心数 * 5）with ThreadPoolExecutor(max_workers=4) as executor:    pass# 使用进程池（默认进程数等于 CPU 核心数）with ProcessPoolExecutor() as executor:    pass

import requestsimport timeimport threadingimport concurrent.futuresdef download_one(url):    resp=requests.get(url)    print(f"read {len(resp.content)} from {url}")def download_all(sites):    for site in sites:        download_one(site)def main():    sites=[        'https://www.baidu.com',        'https://www.ctrip.com',        'https://www.douban.com/',        'https://www.youku.com',        'https://www.deepseek.com/',        'https://time.geekbang.org/',        'https://leetcode.cn/'    ]    start_time=time.perf_counter()    download_all(sites)    end_time=time.perf_counter()    print(f"download {len(sites)} in {end_time-start_time} seconds")if __name__=='__main__':    main()

import requestsimport timeimport threadingimport concurrent.futuresdef download_one(url):    resp=requests.get(url)    print(f"read {len(resp.content)} from {url}")def download_all(sites):    with concurrent.futures.ThreadPoolExecutor(max_workers=5) as executor:        to_do = []        for site in sites:            future = executor.submit(download_one, site)            to_do.append(future)        for future in concurrent.futures.as_completed(to_do):            future.result()def main():    sites=[        'https://www.baidu.com',        'https://www.ctrip.com',        'https://www.douban.com/',        'https://www.youku.com',        'https://www.deepseek.com/',        'https://time.geekbang.org/',        'https://leetcode.cn/'    ]    start_time=time.perf_counter()    download_all(sites)    end_time=time.perf_counter()    print(f"download {len(sites)} in {end_time-start_time} seconds")if __name__=='__main__':    main()