提交任务的两种方式。

同步调用：提交完任务后，就在原地等待任务执行完毕，拿到结果，再执行下一行代码，导致程序是串行执行

异步调用：提交完任务后，不等待任务执行完毕

 

from concurrent.futures import ThreadPoolExecutorimport time,randomdef la(name):    print('%s is laing'%name)    time.sleep(random.randint(3,5))    res = random.randint(7,13)*'#'    return {
   'name':name,'res':res}def weigh(shit):    shit = shit.result() # 异步回掉时，处理接收到的对象    name = shit['name']    size = len(shit['res'])    print('%s 拉了 《%s》kg'%(name,size))if __name__ =='__main__':    pool = ThreadPoolExecutor(13)    # 同步调用    # shit1 = pool.submit(la,'alex').result()    # weigh(shit1)    # shit2 = pool.submit(la, 'huhao').result()    # weigh(shit2)    # shit3 = pool.submit(la, 'zhanbin').result()    # weigh(shit3)    # 异步调用    pool.submit(la, 'alex').add_done_callback(weigh)    pool.submit(la, 'huhao').add_done_callback(weigh)    pool.submit(la, 'zhanbin').add_done_callback(weigh)

 

简单网页爬虫示例：

import requests,timefrom concurrent.futures import ThreadPoolExecutordef get(url):    print('get url',url)    response = requests.get(url)    time.sleep(3)    return {
   'url':url,'content':response.text}def parse(res):    res = res.result()    print('%s parse res is %s'%(res['url'],len(res['content'])))if __name__ == '__main__':    urls = [        'http://www.cnblogs.com/stin',        'https://www.python.org',        'https://www.openstack.org',    ]    pool = ThreadPoolExecutor(2)    for url in urls:        pool.submit(get,url).add_done_callback(parse)