3)线程池进程池

    __author__ = 'lixiang'
    #线程和进程池，python3才有
    from concurrent.futures import ThreadPoolExecutor,ProcessPoolExecutor
    import requests
    url_list={
        "http://baidu.com",
        "http://taobao.com",
    
    }
    
    def task(url):
        response=requests.get(url)
        print(response.content)
    
    
    pool=ThreadPoolExecutor(10)
    #pool=ProcessPoolExecutor(10) 进程
    for url in url_list:
        pool.submit(task,url) #线程池中获取一个线程，执行task函数
    
    #等上面的线程执行完，在往下面运行
    pool.shutdown(wait=True)