如何使用python爬取知乎热榜Top50数据

1、导入第三方库

import urllib.request,urllib.error  #请求网页
from bs4 import BeautifulSoup  # 解析数据
import sqlite3  # 导入数据库
import re # 正则表达式
import time # 获取当前时间

2、程序的主函数

def main():
   # 声明爬取网页
   baseurl = "https://www.zhihu.com/hot"
   # 爬取网页
   datalist = getData(baseurl)
   #保存数据
   dbname = time.strftime("％Y-％m-％d", time.localtime()) #
   dbpath = "zhihuTop50  " + dbname
   saveData(datalist,dbpath)

3、正则表达式匹配数据

#正则表达式
findlink = re.compile(r'<a class="css-hi1lih" href="(.*?)" rel="external nofollow"  rel="external nofollow" ') #问题链接
findid = re.compile(r'<div class="css-blkmyu">(.*?)</div>') #问题排名
findtitle = re.compile(r'<h1 class="css-3yucnr">(.*?)</h1>') #问题标题
findintroduce = re.compile(r'<div class="css-1o6sw4j">(.*?)</div>') #简要介绍
findscore = re.compile(r'<div class="css-1iqwfle">(.*?)</div>') #热门评分
findimg = re.compile(r'<img class="css-uw6cz9" src="(.*?)"/>') #文章配图

4、程序运行结果

5、程序源代码

import urllib.request,urllib.error
from bs4 import BeautifulSoup
import sqlite3
import re
import time

def main():
   # 声明爬取网页
   baseurl = "https://www.zhihu.com/hot"
   # 爬取网页
   datalist = getData(baseurl)
   #保存数据
   dbname = time.strftime("％Y-％m-％d", time.localtime())
   dbpath = "zhihuTop50  " + dbname
   saveData(datalist,dbpath)
   print()
#正则表达式
findlink = re.compile(r'<a class="css-hi1lih" href="(.*?)" rel="external nofollow"  rel="external nofollow" ') #问题链接
findid = re.compile(r'<div class="css-blkmyu">(.*?)</div>') #问题排名
findtitle = re.compile(r'<h1 class="css-3yucnr">(.*?)</h1>') #问题标题
findintroduce = re.compile(r'<div class="css-1o6sw4j">(.*?)</div>') #简要介绍
findscore = re.compile(r'<div class="css-1iqwfle">(.*?)</div>') #热门评分
findimg = re.compile(r'<img class="css-uw6cz9" src="(.*?)"/>') #文章配图

def getData(baseurl):
   datalist = []
   html = askURL(baseurl)
   # print(html)

soup = BeautifulSoup(html,'html.parser')
   for item in soup.find_all('a',class_="css-hi1lih"):
       # print(item)
       data = []
       item = str(item)

Id = re.findall(findid,item)
       if(len(Id) == 0):
           Id = re.findall(r'<div class="css-mm8qdi">(.*?)</div>',item)[0]
       else: Id = Id[0]
       data.append(Id)
       # print(Id)

Link = re.findall(findlink,item)[0]
       data.append(Link)
       # print(Link)

Title = re.findall(findtitle,item)[0]
       data.append(Title)
       # print(Title)

Introduce = re.findall(findintroduce,item)
       if(len(Introduce) == 0):
           Introduce = " "
       else:Introduce = Introduce[0]
       data.append(Introduce)
       # print(Introduce)

Score = re.findall(findscore,item)[0]
       data.append(Score)
       # print(Score)

Img = re.findall(findimg,item)
       if (len(Img) == 0):
           Img = " "
       else: Img = Img[0]
       data.append(Img)
       # print(Img)
       datalist.append(data)
   return datalist
def askURL(baseurl):
   # 设置请求头
   head = {
       # "User-Agent": "Mozilla/5.0 (Windows NT 10.0;Win64;x64) AppleWebKit/537.36(KHTML, likeGecko) Chrome/80.0.3987.163Safari/537.36"
       "User-Agent": "Mozilla / 5.0(iPhone;CPUiPhoneOS13_2_3likeMacOSX) AppleWebKit / 605.1.15(KHTML, likeGecko) Version / 13.0.3Mobile / 15E148Safari / 604.1"
   }
   request = urllib.request.Request(baseurl, headers=head)
   html = ""
   try:
       response = urllib.request.urlopen(request)
       html = response.read().decode("utf-8")
       # print(html)
   except urllib.error.URLError as e:
       if hasattr(e, "code"):
           print(e.code)
       if hasattr(e, "reason"):
           print(e.reason)
   return html
   print()
def saveData(datalist,dbpath):
   init_db(dbpath)
   conn = sqlite3.connect(dbpath)
   cur = conn.cursor()

for data in datalist:
       sql = '''
       insert into Top50(
       id,info_link,title,introduce,score,img)
       values("％s","％s","％s","％s","％s","％s")'''％(data[0],data[1],data[2],data[3],data[4],data[5])
       print(sql)
       cur.execute(sql)
       conn.commit()
   cur.close()
   conn.close()
def init_db(dbpath):
   sql = '''
   create table Top50
   (
   id integer primary key autoincrement,
   info_link text,
   title text,
   introduce text,
   score text,
   img text
   )
   '''
   conn = sqlite3.connect(dbpath)
   cursor = conn.cursor()
   cursor.execute(sql)
   conn.commit()
   conn.close()

if __name__ =="__main__":
   main()

来源：https://blog.csdn.net/gets_s/article/details/115096619