爬虫模块-requests

1、requests模块

requests模块的底层是urllib，但是比urllib更强大也更加简洁。

基本方法:

• requests.get()
• requests.post()
• requests.request()
• requests.head()

目前阶段只学习到了get和post方法。

其中get方法是获得请求的，post方法是发送请求的。

2、爬取百度贴吧网页实例

# coding=utf-8
import requests

class TiebaSpider:
    def __init__(self,tieba_name):
        self.tieba_name = tieba_name
        self.tieba_url = "https://tieba.baidu.com/f?kw="+ tieba_name +"&ie=utf-8&pn={}"
        self.header = {"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.116 Safari/537.36"}

    def getUrlList(self):
        # url_list = []
        # for i in range(3):
        #     url_list.append(self.tieba_url.format(i*50))
        # return url_list
        # 下方的是简洁写法，是主流的写法
        return [self.tieba_url.format(i*50) for i in range(3)]

    def get_content(self,url):
        print(url)
        response = requests.get(url,headers = self.header)
        return response.content.decode()

    def save_html(self,response,index):
        file_name = "{}吧-第{}页.html".format(self.tieba_name,index)
        # with open as 变量名 方式打开文件会在最后关闭文件
        with open(file_name,"w",encoding="utf-8") as f:
            f.write(response)

    def run(self):
        #1.获取要爬的url列表
        url_list = self.getUrlList()
        #2.开始爬取
        for url in url_list:
            response = self.get_content(url)
            # 3.保存文件
            self.save_html(response,url_list.index(url)+1)

if __name__ == '__main__':
    tieba_name = input("请输入要爬取的贴吧名称:")
    spider = TiebaSpider(tieba_name)
    spider.run()