目标 

aHR0cHMlM0EvL3d3dy56b25naGVuZy5jb20vcmFuay9kZXRhaWxzLmh0bWwlM0ZydCUzRDUlMjZkJTNEMSUyNnAlM0Qy

来到页面

先请求再说

import requests

def dowmload_one_page(url):
    header = {
        'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/105.0.0.0 Safari/537.36'}
    resp = requests.get(url=url,headers=header)
    print(resp.text)

if __name__ == '__main__':
    dowmload_one_page('https://www.xxxxxxxx.com/rank/details.html?rt=5&d=1&p=2')

 没有乱码，然后到页面分析去

所有的学习都在这个大的div里面

 拉到最后面会看到俩个没有用的div，可以去掉

导入库

from lxml import etree

定位到列表

html = etree.HTML(resp.text)
    div_list = html.xpath('/html/body/div[2]/div[4]/div[2]/div[3]')[0]  # 加个0给它整成列表
    divs = div_list.xpath('./div')[:-2]  # 后面多了来个列表，不是需要的
    print(len(divs))

一共有20个

全部提取出来

保存一下

import requests,csv
from lxml import etree
f = open("da.csv",mode="w", encoding="utf-8")
csvwriter = csv.writer(f)
def dowmload_one_page(url):
    header = {
        'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/105.0.0.0 Safari/537.36'}
    resp = requests.get(url=url,headers=header)
    # print(resp.text)
    html = etree.HTML(resp.text)
    div_list = html.xpath('/html/body/div[2]/div[4]/div[2]/div[3]')[0]  # 加个0给它整成列表
    divs = div_list.xpath('./div')[:-2]  # 后面多了来个列表，不是需要的
    # print(len(divs))
    for div in divs:
        name = div.xpath('./div/div/a/text()')
        csvwriter.writerow(name)
        # print(name)
    print("保存完成")
if __name__ == '__main__':
    dowmload_one_page('https://www.xxxx.com/rank/details.html?rt=5&d=1&p=2')

 回到页面，可以看到一共是10页，如果是这样改代码

if __name__ == '__main__':
        for i in range(1,11):
            dowmload_one_page ('https://www.xxx.com/rank/details.html?rt=5&d=1&p={i}')
    

的话，会发现效率很低，贼慢，如果需要爬的页面很多的那种的话，可以挂电脑去看电视了，还有可能会出错，这时候我们就需要线程池了

导入库

from concurrent.futures import ThreadPoolExecutor

修改代码如下

if __name__ == '__main__':
    with ThreadPoolExecutor(50) as t:  
        for i in range(1,11):
            t.submit(dowmload_one_page, f'https://www.xxxx.com/rank/details.html?rt=5&d=1&p={i}')
    print("全部下载完毕")

ThreadPoolExecutor(50)的意思是创建50个线程池，t.submit呢是把任务交给线程池

运行后瞬间完成，如果是单独的for循环估计要好几秒