Python爬虫系列-Requests库详解

Requests基于urllib，比urllib更加方便，可以节约我们大量的工作，完全满足HTTP测试需求。

实例引入

 import requests

 response = requests.get('https://www.baidu.com/')

 print(type(response))

 print(response.status_code)

 print(type(response.text))

 print(response.cookies)

各种请求方式

 import requests

 requests.post('http://httpbin.org/post')

 requests.put('http://httpbin.org/put')

 requests.delete('http://httpbin.org/delete')

 requests.head('http://httpbin.org/gett')

 requests.head('http://httpbin.org/get')

 requests.options('http://httpbin.org/get')

基本GET请求

 import requests

 response = requests.get('http://httpbin.org/get')

 print(response.text)

带参数的GET请求

import requests

 response = requests.get('http://httpbin.org/get?name=germey&age=22')

 print(response.text)

import requests

 data = { 'name':'germery','age':22 }

 response = requests.get('http://httpbin.org/get',params=data)

 print(response.text)

解析json

 import requests

 response = requests.get('http://httpbin.org/get')

 print(type(response.text))

 print(response.json())  # 与json.loads(response.text)完全一样

 print(type(response.json()))

获取二进制数据

import requests

 response = requests.get('https://github.com/favicon.ico')

 print(type(response.text),type(response.content))

下载图片

import requests

 response = requests.get('https://github.com/favion.ico')

 with open('favicon.ico','wb') as f:

     f.write(response.content)

添加headers

import requests

 headers = { 'User-Agent':'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.77 Safari/537.36' }

 response = requests.get('https://www.zhihu.com/explore',headers=headers)

基本POST请求

import requests

data = { 'name':'germey','age':22 }

response = requests.post('http://httpbin.org/post',data=data)

print(response.text)

添加headers

 import requests

 data = {'name':'germey','age':22}

 headers = { 'User-Agent':'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.77 Safari/537.36' }

 response = requests.post('http://httpbin.org/post',data=data,headers=headers)

 print(response.json())

响应

response属性

import requests

 response = requests.get('http://www.jianshu.com')

print(type(response.status_code),response.status_code)

 print(type(response.headers),response.headers)

<class 'requests.structures.CaseInsensitiveDict'> {'Date': 'Tue, 27 Nov 2018 20:03:06 GMT', 'Content-Type': 'text/html', 'Transfer-Encoding': 'chunked', 'Connection': 'keep-alive', 'Server': 'Tengine', 'Strict-Transport-Security': 'max-age=31536000; includeSubDomains; preload', 'Content-Encoding': 'gzip', 'X-Via': '1.1 dianxinxiazai180:5 (Cdn Cache Server V2.0), 1.1 PSjsntdx3xf38:1 (Cdn Cache Server V2.0)'}

 print(type(response.cookies),response.cookies)

 print(type(response.url),response.url)

 print(type(response.history),response.history)

状态码判断：

 import requests

 response = requests.get('http://www.jianshu.com')

 exit() if not response.status_code==requests.codes.ok else print('Request Successfully')

 import requests

 response = requests.get('http://www.jianshu.com')

 exit() if not response.status_code==200 else print('Request Successfully')

Requests高级操作

文件上传

 import requests

 files = {'files':open('favicon.ico','rb')}

 response = requests.post('http://httpbin.org/post',files=files)

 print(response.text)

获取cookie值

import requests

 response = requests.get('http://www.baidu.com')

 print(response.cookies)

 for key,value in response.cookies.items():

     print(key+'='+value)

会话维持 模拟登录

import requests

 requests.get('http://httpbin.org/cookies/set/number/123456789')

 response = requests.get('http://httpbin.org/cookies')

 print(response.text)

s = requests.Session()

 s.get('http://httpbin.org/cookies/set/number/123456789')

 response = s.get('http://httpbin.org/cookies')

 print(response.text)

证书验证

import requests

 response = requests.get('https://www.12306.cn')

 print(response.status_code)

response = requests.get('https://www.12306.cn',verify=False)

添加证书

response = requests.get('https://www.12306.cn',cert=('/path/server.crf','/path/key'))

代理设置

 import requests

 proxies = {

   'http':'http://222.74.61.98:53281',

 # 'http':'http://user:[email protected]:53281'  #添加密码

  'https':'https://114.119.116.92:61066'

  }

 response = requests.get('https://www.taobao.com',proxies=proxies)

 print(response.status_code)

使用socks代理设置

首先安装requests[socks]支持：

 pip3 install 'requests[socks]'

import requests

proxies = {

 'http':'socks5://127.0.0.1:1080',

 'https':'socks5://127.0.0.1:1080'

 }

 response = requests.get('https://www.taobao.com',proxies=proxies)

 print(response.status_code)

超时设置与捕获

import requests

from requests.exceptions import ReadTimeout

try:

     response = requests.get("http://www.taobao.com",timeout=0.01)

     print(response.status_code)

 except ReadTimeout:

     print('Timeout')

认证设置

import requests

from requests.auth import HTTPBasicAuth

 r = requests.get('http://120.27.34.24:9001',auth=HTTPBasicAuth('user',123))

# r = requests.get('http://120.27.34.24:9001',auth= ('user',123))

异常处理

import requests

 from requests.exceptions import ReadTimeout,ConnectionError,HTTPError,RequestException

 try:

     response = requests.get('http://httpbin.org/get',timeout=0.5)

     print(response.status_code)

 except ReadTimeout:

    print('Timeout')

 except ConnectionError:

    print('Timeout')

 except HTTPError:

     print('Http Error')

 except RequestException:

     print('Error')