python 爬虫请求模块requests详解

(编辑：jimmy 日期: 2024/11/16 浏览：3 次 )

requests

相比urllib，第三方库requests更加简单人性化，是爬虫工作中常用的库

requests安装

初级爬虫的开始主要是使用requests模块
安装requests模块：
Windows系统：
cmd中：

pip install requests

mac系统中：
终端中：

pip3 install requests

requests库的基本使用

import requests

url = 'https://www.csdn.net/'
reponse = requests.get(url)
#返回unicode格式的数据(str) 
print(reponse.text)

响应对象response的"text-align: center">

例如：
200 : 请求成功
301 : 永久重定向
302 : 临时重定向
403 : 服务器拒绝请求
404 : 请求失败(服务器"htmlcode">

# 导入requests
import requests
# 调用requests中的get()方法来向服务器发送请求，括号内的url参数就是我们
# 需要访问的网址，然后将获取到的响应通过变量response保存起来
url = 'https://www.csdn.net/' # csdn官网链接链接
response = requests.get(url)
print(response.status_code) # response.status_code: 检查响应的状态码

200

请求"htmlcode">

p = requests.get(url)
p = requests.post(url)
p = requests.put(url,data={'key':'value'})
p = requests.delete(url)
p = requests.head(url)
p = requests.options(url)

GET请求

HTTP默认的请求方法就是GET
* 没有请求体
* 数据必须在1K之内！
* GET请求数据会暴露在浏览器的地址栏中

GET请求常用的操作：
1. 在浏览器的地址栏中直接给出URL，那么就一定是GET请求
2. 点击页面上的超链接也一定是GET请求
3. 提交表单时，表单默认使用GET请求，但可以设置为POST

POST请求

(1). 数据不会出现在地址栏中
(2). 数据的大小没有上限
(3). 有请求体
(4). 请求体中如果存在中文，会使用URL编码！

requests.post()用法与requests.get()完全一致，特殊的是requests.post()有一个data参数，用来存放请求体数据

请求头

当我们打开一个网页时，浏览器要向网站服务器发送一个HTTP请求头，然后网站服务器根据HTTP请求头的内容生成当此请求的内容发送给服务器。
我们可以手动设定请求头的内容：

import requests

header = { 'User-Agent':'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.88 Safari/537.36'}

url = 'https://www.csdn.net/'
reponse = requests.get(url,headers=header)
#打印文本形式
print(reponse.text)

requests设置代理

使"htmlcode">

import requests
#这段cookies是从CSDN官网控制台中复制的
header = { 'User-Agent':'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.88 Safari/537.36',
      'cookie': 'uuid_tt_dd=10_30835064740-1583844255125-466273; dc_session_id=10_1583844255125.696601; __gads=ID=23811027bd34da29:T=1583844256:S=ALNI_MY6f7VlmNJKxrkHd2WKUIBQ34Bbnw; UserName=xdc1812547560; UserInfo=708aa833b2064ba9bb8ab0be63866b58; UserToken=708aa833b2064ba9bb8ab0be63866b58; UserNick=xdc1812547560; AU=F85; UN=xdc1812547560; BT=1590317415705; p_uid=U000000; Hm_ct_6bcd52f51e9b3dce32bec4a3997715ac=6525*1*10_30835064740-1583844255125-466273!5744*1*xdc1812547560; Hm_up_6bcd52f51e9b3dce32bec4a3997715ac=%7B%22islogin%22%3A%7B%22value%22%3A%221%22%2C%22scope%22%3A1%7D%2C%22isonline%22%3A%7B%22value%22%3A%221%22%2C%22scope%22%3A1%7D%2C%22isvip%22%3A%7B%22value%22%3A%220%22%2C%22scope%22%3A1%7D%2C%22uid_%22%3A%7B%22value%22%3A%22xdc1812547560%22%2C%22scope%22%3A1%7D%7D; log_Id_click=1; Hm_lvt_feacd7cde2017fd3b499802fc6a6dbb4=1595575203; Hm_up_feacd7cde2017fd3b499802fc6a6dbb4=%7B%22islogin%22%3A%7B%22value%22%3A%221%22%2C%22scope%22%3A1%7D%2C%22isonline%22%3A%7B%22value%22%3A%221%22%2C%22scope%22%3A1%7D%2C%22isvip%22%3A%7B%22value%22%3A%220%22%2C%22scope%22%3A1%7D%2C%22uid_%22%3A%7B%22value%22%3A%22xdc1812547560%22%2C%22scope%22%3A1%7D%7D; Hm_ct_feacd7cde2017fd3b499802fc6a6dbb4=5744*1*xdc1812547560!6525*1*10_30835064740-1583844255125-466273; Hm_up_facf15707d34a73694bf5c0d571a4a72=%7B%22islogin%22%3A%7B%22value%22%3A%221%22%2C%22scope%22%3A1%7D%2C%22isonline%22%3A%7B%22value%22%3A%221%22%2C%22scope%22%3A1%7D%2C%22isvip%22%3A%7B%22value%22%3A%220%22%2C%22scope%22%3A1%7D%2C%22uid_%22%3A%7B%22value%22%3A%22xdc1812547560%22%2C%22scope%22%3A1%7D%7D; Hm_ct_facf15707d34a73694bf5c0d571a4a72=5744*1*xdc1812547560!6525*1*10_30835064740-1583844255125-466273; announcement=%257B%2522isLogin%2522%253Atrue%252C%2522announcementUrl%2522%253A%2522https%253A%252F%252Flive.csdn.net%252Froom%252Fyzkskaka%252Fats4dBdZ%253Futm_source%253D908346557%2522%252C%2522announcementCount%2522%253A0%257D; Hm_lvt_facf15707d34a73694bf5c0d571a4a72=1596946584,1597134917,1597155835,1597206739; searchHistoryArray=%255B%2522%25E8%258F%259C%25E9%25B8%259FIT%25E5%25A5%25B3%2522%252C%2522%25E5%25AE%25A2%25E6%259C%258D%2522%255D; log_Id_pv=7; log_Id_view=8; dc_sid=c0efd34d6da090a1fccd033091e0dc53; TY_SESSION_ID=7d77f76f-a4b1-43ef-9bb5-0aebee8ee475; c_ref=https%3A//www.baidu.com/link; c_first_ref=www.baidu.com; c_first_page=https%3A//www.csdn.net/; Hm_lvt_6bcd52f51e9b3dce32bec4a3997715ac=1597245305,1597254589,1597290418,1597378513; c_segment=1; dc_tos=qf1jz2; Hm_lpvt_6bcd52f51e9b3dce32bec4a3997715ac=1597387359'}

url = 'https://www.csdn.net/'
reponse = requests.get(url,headers=header)
#打印文本形式
print(reponse.text)

session

session ：通过在服务端记录的信息确定"text-align: center">

 import requests
url = 'https://inv-veri.chinatax.gov.cn/'

resp = requests.get(url)

print(resp.text)

它报了一个错

我们来修改一下代码

import requests
url = 'https://inv-veri.chinatax.gov.cn/'

resp = requests.get(url,verify = False)

print(resp.text)

我们的代码又能成功爬取了

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