爬虫的运用

首先是爬”中国最好的大学“这个网站，相应代码如下（应为我是06号所以我爬的是2017）

 1 # -*- coding: utf-8 -*-
 2 """
 3 Created on Wed May 22 22:34:04 2019
 4 
 5 @author: m1353
 6 """
 7 
 8 import requests
 9 from bs4 import BeautifulSoup
10 alluniv = []
11 def getHTMLText(url):
12     try:
13         r = requests.get(url,timeout = 30)
14         r.raise_for_status()
15         r.encoding = 'utf-8'
16         return r.text
17     except:
18         return "error"
19 def fillunivlist(soup):
20     data=soup.find_all('tr')
21     for tr in data:
22         ltd =tr.find_all('td')
23         if len(ltd)==0:
24             continue
25         singleuniv=[]
26         for td in ltd:
27             singleuniv.append(td.string)
28         alluniv.append(singleuniv)
29 def printunivlist(num):
30     print("{1:^2}{2:{0}^10}{3:{0}^6}{4:{0}^4}{5:{0}^10}".format(chr(12288),"排名","学校名字","省份","总分","培养规模"))
31     for i in range(num):
32         u=alluniv[i]
33         print("{1:^4}{2:{0}^10}{3:{0}^5}{4:{0}^8.1f}{5:{0}^10}".format(chr(12288),u[0],u[1],u[2],eval(u[3]),u[6]))
34 def main(num):
35     url = "http://www.zuihaodaxue.cn/zuihaodaxuepaiming2017.html"
36     html=getHTMLText(url)
37     soup=BeautifulSoup(html,"html.parser")
38     fillunivlist(soup)
39     printunivlist(num)
40 main(10)

main函数中的参数是索取其中的排名信息的个数

　　执行效果如下

然后没有成功，但是我的代码没有错。。。因为我能爬2016，2019的截图如下

2016的如下

仅此修改了网页地址的一个数字

然后是2019的，如下图

嗯，都可以出来，所以我无辜的=3=

然后是开始爬谷歌网（我是06号）

代码如下（和上面的差不太多）

 1 # -*- coding: utf-8 -*-
 2 """
 3 Created on Wed May 22 22:34:04 2019
 4 
 5 @author: m1353
 6 """
 7 
 8 import requests
 9 from bs4 import BeautifulSoup
10 alluniv = []
11 def getHTMLText(url):
12     try:
13         r = requests.get(url,timeout = 30)
14         r.raise_for_status()
15         r.encoding = 'utf-8'
16         return r.text
17     except:
18         return "error"
19 def xunhuang(url):
20     for i in range(20):
21         getHTMLText(url)
22 def fillunivlist(soup):
23     data=soup.find_all('tr')
24     for tr in data:
25         ltd =tr.find_all('td')
26         if len(ltd)==0:
27             continue
28         singleuniv=[]
29         for td in ltd:
30             singleuniv.append(td.string)
31         alluniv.append(singleuniv)
32 def printf():
33     print("\n")
34     print("\n")
35     print("\n")
36 def main():
37     url = "http://www.google.com"
38     html=getHTMLText(url)
39     xunhuang(url)
40     print(html)
41     soup=BeautifulSoup(html,"html.parser")
42     fillunivlist(soup)
43     print(html)
44     printf()
45     print(soup.title)
46     printf()
47     print(soup.head)
48     printf()
49     print(soup.body)
50 main()