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from concurrent.futures import ThreadPoolExecutor,ProcessPoolExecutor print('ThreadPoolExecutor继承关系：',ThreadPoolExecutor.__mro__) print('ThreadPoolExecutor属性：',[attr for attr in dir(ThreadPoolExecutor) if not attr.startswith('_')]) print('ProcessPoolExecutor继承关系：',ProcessPoolExecutor.__mro__) print('ThreadPoolExecutor属性：',[attr for attr in dir(ProcessPoolExecutor) if not attr.startswith('_')])
都继承自futures._base.Executor类，拥有三个重要方法map、submit和shutdow，这样看起来就很简单了
（2）再看下futures._base.Executor基类实现
View Code提供了map、submit、shutdow和with方法，下面首先对这个几个方法的使用进行说明
函数原型：def map(self, fn, *iterables, timeout=None, chunksize=1)
map函数和python自带的map函数用能类型，只不过该map函数从迭代器获取参数后异步执行，timeout用于设置超时时间
参数chunksize的理解：
The size of the chunks the iterable will be broken into before being passed to a child process. This argument is only used by ProcessPoolExecutor; it is ignored by ThreadPoolExecutor.
例：
from concurrent.futures import ThreadPoolExecutor import time import requests def download(url): headers = {'User-Agent':'Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0', 'Connection':'keep-alive',
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![就库的范围，个人认为网络爬虫必备库知识包括urllib、requests、re、BeautifulSoup、concurrent.futures，接下来将结对concurrent.futures库的使用方法进行总结建议阅读本博的博友先阅读下上篇博客：](upload/201812041604021460.png") 9px 0px no-repeat rgb(255, 255, 163); border: 2px solid rgb(239, 239, 239); color: rgb(51, 51, 51); min-height: 35px; line-height: 1.6em; clear: both; font-family: "Microsoft Yahei"; font-size: 14px; box-shadow: rgb(170, 170, 170) 0px 0px 8px;){kind=link}
