python3爬虫实例（二）-bs4抓取大学排名储存为txt

运行版本：
Python 3.7.0
完整代码如下：

# coding:utf-8
import requests
from bs4 import BeautifulSoup
import  bs4


def gethtml(url,headers):
    response =  requests.get(url,headers=headers)
    try:
        if response.status_code == 200:
            print('抓取成功网页长度：',len(response.text))
            response.encoding = 'utf-8'
            return response.text
    except BaseException as e:
        print('抓取出现错误：',e)

def getsoup(html):
    soup = BeautifulSoup(html,'lxml')
    for tr in soup.find('tbody').children:  #生成tr的tag列表
        if isinstance(tr,bs4.element.Tag):
            td = tr('td')          #循环获取所有tr标签下的td标签，并生成tag列表
            t = [td[0].string, td[1].string,'    ',td[2].string,'   ',td[3].string]   #提取前四td字符串
            list.append(t)

def write_data(list):
   for i in list:   #循环提取list中的元素
    with open('daxue.txt','a') as  data:
                print(i,file=data)          #写入文件


if __name__ == '__main__':
    list = []
    url = 'http://www.zuihaodaxue.com/shengyuanzhiliangpaiming2018.html'
    headers = {
        'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36'
    }
    html = gethtml(url,headers)
    getsoup(html)
    write_data(list)

运行结果：