from urllib import request
from bs4 import BeautifulSoup #Beautiful Soup是一个可以从HTML或XML文件中提取结构化数据的Python库
#构造头文件，模拟浏览器访问
url="http://www.jianshu.com"
headers = {'User-Agent':'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.87 Safari/537.36'}
page = request.Request(url,headers=headers)
page_info = request.urlopen(page).read().decode('utf-8')#打开Url,获取HttpResponse返回对象并读取其ResposneBody
# 将获取到的内容转换成BeautifulSoup格式，并将html.parser作为解析器
soup = BeautifulSoup(page_info, 'html.parser')
# 以格式化的形式打印html
#print(soup.prettify())
titles = soup.find_all('a', 'title')# 查找所有a标签中class='title'的语句
'''''
# 打印查找到的每一个a标签的string和文章链接
  for title in titles:
    print(title.string)
    print("http://www.jianshu.com" + title.get('href'))
'''
#open()是读写文件的函数,with语句会自动close()已打开文件
with open(r"D:\articles.txt","w") as file:    #在磁盘以只写的方式打开/创建一个名为 articles 的txt文件
  for title in titles:
    file.write(title.string+'\n')
    file.write("http://www.jianshu.com" + title.get('href')+'\n\n')