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简易版python爬虫--通过关键字爬取网页

背景:
帮同学写了个爬虫程序,特此记录,怕以后忘了
这里是爬取百度https://www.baidu.com
不为什么,主要就是百度老实,能爬,爬着简单,爬着不犯法。。。

关键字爬取基本模板:

import requests
from bs4 import BeautifulSoup
import random
import time

defsearchbaidu(keyword):
        url =f"https://www.baidu.com/s?wd={keyword}"
        user_agents =['Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edge/20.10240.16384 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edg/85.0.564.44 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edg/80.0.361.109 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edg/80.0.361.57 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edg/79.0.309.68 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edg/78.0.276.19 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edg/77.0.235.9 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edg/75.0.139.8 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edg/74.1.96.24 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edg/73.0.3683.75 Safari/537.36']
        headers ={'User-Agent': random.choice(user_agents)}

        response = requests.get(url, headers=headers)
        time.sleep(random.uniform(0.5,3))# 设置访问频率限制
        soup = BeautifulSoup(response.content,"html.parser")
        results = soup.find_all("div", class_="result")for result in results:try:
                title = result.find("h3").text
                link = result.find("a")["href"]print(title)print(link)except:continue

说明:

随机用户,反反爬虫

这个程序是有一点小优化的,主要就是进行了一点点小小的反反爬虫措施
如:

        user_agents =['Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edge/20.10240.16384 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edg/85.0.564.44 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edg/80.0.361.109 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edg/80.0.361.57 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edg/79.0.309.68 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edg/78.0.276.19 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edg/77.0.235.9 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edg/75.0.139.8 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edg/74.1.96.24 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edg/73.0.3683.75 Safari/537.36']
        headers ={'User-Agent': random.choice(user_agents)}
        time.sleep(random.uniform(0.5,3))# 设置访问频率限制

这一步是为了获取一个请求对象,说白了就是模拟一个用户来访问,由此避开百度的反爬机制捏。不过百度这样好爬,也方便了咱们这些初学者学习嘛~
综上,通过随机获取列表里的数值来模拟出随机的访客

获取数据

        response = requests.get(url, headers=headers)
        soup = BeautifulSoup(response.content,"html.parser")
        results = soup.find_all("div", class_="result")

requests.get(url, headers=headers)就是以headers的身份获取链接里面的内容

BeautifulSoup(response.content, “html.parser”)就是提取出内容里面的html部分

soup.find_all(“div”, class_=“result”)就是寻找html里所有class为result的div。

展示数据:

for result in results:try:
                title = result.find("h3").text
                link = result.find("a")["href"]print(title)print(link)except:continue

title = result.find(“h3”).text
link = result.find(“a”)[“href”]
result.find()也就是寻找标签为()里面内容的东西,这里也就不意义赘述了

总代码:

import requests
from bs4 import BeautifulSoup
import random
import time

defsearchbaidu(keyword):
        url =f"https://www.baidu.com/s?wd={keyword}"
        user_agents =['Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edge/20.10240.16384 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edg/85.0.564.44 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edg/80.0.361.109 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edg/80.0.361.57 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edg/79.0.309.68 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edg/78.0.276.19 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edg/77.0.235.9 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edg/75.0.139.8 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edg/74.1.96.24 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Edg/73.0.3683.75 Safari/537.36']
        headers ={'User-Agent': random.choice(user_agents)}

        response = requests.get(url, headers=headers)
        time.sleep(random.uniform(0.5,3))# 设置访问频率限制
        soup = BeautifulSoup(response.content,"html.parser")
        results = soup.find_all("div", class_="result")for result in results:try:
                title = result.find("h3").text
                link = result.find("a")["href"]print(title)print(link)except:continue
 searchbaidu("python")

调用函数寻找关键字为"python"的内容
结果:
在这里插入图片描述

大概就这样了~~


本文转载自: https://blog.csdn.net/qq_62791684/article/details/129774761
版权归原作者 泉绮 所有, 如有侵权,请联系我们删除。

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