中国大学排名爬虫代码实例分析
“中国大学排名定向爬虫”实例介绍
网址:http://www.zuihaodaxue.cn/zuihaodaxuepaiming2016.html
定向爬虫可行性
<tbody class="hidden_zhpm" style="text-align:center;">
<tr class="alt"><td>1</td>
<td><div align="left">清华大学</div></td>
<td>北京市</td><td>95.9</td><td class="hidden-xs need-hidden indicator5">100.0</td><td class="hidden-xs need-hidden indicator6" style="display:none;">97.90%</td><td class="hidden-xs need-hidden indicator7" style="display:none;">37342</td><td class="hidden-xs need-hidden indicator8" style="display:none;">1.298</td><td class="hidden-xs need-hidden indicator9" style="display:none;">1177</td><td class="hidden-xs need-hidden indicator10" style="display:none;">109</td><td class="hidden-xs need-hidden indicator11" style="display:none;">1137711</td><td class="hidden-xs need-hidden indicator12" style="display:none;">1187</td><td class="hidden-xs need-hidden indicator13" style="display:none;">593522</td></tr><tr><td>2</td>
<td><div align="left">北京大学</div></td>
<td>北京市</td><td>82.6</td><td class="hidden-xs need-hidden indicator5">98.9</td><td class="hidden-xs need-hidden indicator6" style="display:none;">95.96%</td><td class="hidden-xs need-hidden indicator7" style="display:none;">36137</td><td class="hidden-xs need-hidden indicator8" style="display:none;">1.294</td><td class="hidden-xs need-hidden indicator9" style="display:none;">986</td><td class="hidden-xs need-hidden indicator10" style="display:none;">87</td><td class="hidden-xs need-hidden indicator11" style="display:none;">439403</td><td class="hidden-xs need-hidden indicator12" style="display:none;">799</td><td class="hidden-xs need-hidden indicator13" style="display:none;">7343</td></tr><tr class="alt"><td>3</td>
<td><div align="left">浙江大学</div></td>
<td>浙江省</td><td>80</td><td class="hidden-xs need-hidden indicator5">88.8</td><td class="hidden-xs need-hidden indicator6" style="display:none;">96.46%</td><td class="hidden-xs need-hidden indicator7" style="display:none;">41188</td><td class="hidden-xs need-hidden indicator8" style="display:none;">1.059</td><td class="hidden-xs need-hidden indicator9" style="display:none;">803</td><td class="hidden-xs need-hidden indicator10" style="display:none;">86</td><td class="hidden-xs need-hidden indicator11" style="display:none;">959511</td><td class="hidden-xs need-hidden indicator12" style="display:none;">833</td><td class="hidden-xs need-hidden indicator13" style="display:none;">64392</td></tr><tr><td>4</td>
定向爬虫可行性:通过robots协议查看
http://www.zuihaodaxue.cn/robots.txt
程序的结构设计
步骤1:从网络上获取大学排名网页内容
getHTMLText()
步骤2:提取网页内容中信息到合适的数据结构
fillUnivList()
步骤3:利用数据结构展示并输出结果
printUnivList()
"中国大学排名定向爬虫"实例编写
import requests
from bs4 import BeautifulSoup
def getHTMLText(url):
try:
r = requests.get(url,timeout=30)
r.raise_for_status()
r.encoding = r.apparent_encoding
return r.text
except:
return""
import bs4
def fillUnivList(ulist,html):
soup = BeautifulSoup(html,"html.parser")
for tr in soup.find('tbody').children:
if isinstance(tr,bs4.element.Tag):
tds = tr('td')
ulist.append([tds[0].string,tds[1].string,tds[3].string])
def printUnivList(ulist,num):
tplt = "{0:^10}\t{1:{3}^10}\t{2:^10}"
print("{:^10}\t{:^6}\t{:^10}".format("排名","学校名称","总分",chr(12288)))
for i in range(num):
u=ulist[i]
print(tplt.format(u[0],u[1],u[2],chr(12288)))
def main():
uinfo = []
url = 'http://www.zuihaodaxue.cn/zuihaodaxuepaiming2016.html'
html = getHTMLText(url)
fillUnivList(uinfo,html)
printUnivList(uinfo,20) #20 univs
main()