python 爬虫 python100例测试

from bs4 import BeautifulSoup
import requests
import  time
url ='http://www.runoob.com/python/python-100-examples.html'
headers = {
"User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.102 Safari/537.36"
}
r = requests.get(url, headers = headers).content.decode('utf8')
soup_start = BeautifulSoup(r,'html.parser')
links = soup_start.find(id = 'content').find_all("a",limit = 100)
num = 1
for i in links:
        url2 = 'http://www.runoob.com' + i.attrs["href"]
        r2 = requests.get(url2,headers= headers).content.decode('utf8')
        soup_title = BeautifulSoup(r2,"html.parser")
        title = soup_title.find(id = 'content').find_all('p')[1].text
        try:
                answer = soup_title.find(id='content').find_all(class_ = 'hl-main')[0].text
        except:
                answer = soup_title.find(id='content').find_all('pre')[0].text

        with open ("python100.txt",'a+') as file:
                file.write(title +'\n'+ answer+ '\n' + '-'*60 + '\n')
        print('爬取页数{}',format(num))
        num += 1