Python requests详解

•  Requests

参考文档：http://docs.python-requests.org/zh_CN/latest/user/quickstart.html

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

#文本形式的网页源码
print(response.text)

#二进制流形式打印
print(response.content)

#返回JSON格式，可能抛出异常
print(response.json)

#状态码
print(response.status_code)

#请求url
print(response.url)

#头信息
print(response.headers)

#cookie信息
print(response.cookies)

• 传递参数

   

import requests

payload = {'key1': 'value1', 'key2': 'value2', 'key3': None}
r = requests.get('http://httpbin.org/get', params=payload)
print(r.url)

• 请求方式

 

requests.get('http://httpbin.org/get')
requests.post('http://httpbin.org/post')
requests.put('http://httpbin.org/put')
requests.delete('http://httpbin.org/delete')
requests.head('http://httpbin.org/get')
requests.options('http://httpbin.org/get')

• post访问

import requests
payload = {'key1': 'value1', 'key2': 'value2'}
r = requests.post("http://httpbin.org/post", data=payload)
print(r.text)

• 传递文件

import requests
url = 'http://httpbin.org/post'
files = {'file': open('wyl.xls', 'rb')}
r = requests.post(url, files=files)

• 传递字符串

import requests
import json
url = 'https://xxxxxxxx'
payload = {'some': 'data'}
r = requests.post(url, data=json.dumps(payload))
#或者
r = requests.post(url, json=payload)

• 超时设置

 requests.get('http://xxxxx.com', timeout=1) 

• 代理

import requests
proxies = {
  'http': 'http://10.10.1.10:3128',
  'https': 'http://10.10.1.10:1080',
}
requests.get('http://xxxx.com', proxies=proxies)

• 重定向与请求历史

import requests
s=requests.get('http://github.com')
print(s.url)
print(s.status_code)
r=requests.get('http://github.com', allow_redirects=False)
print(r.url)
print(r.history)
r=requests.head('http://github.com');
print(r.url)
print(r.status_code)
r=requests.head('http://github.com', allow_redirects=True)
print(r.url)
print(r.history)

• 异常处理

#所有Requests显式抛出的异常都继承自 requests.exceptions.RequestException

import requests
from requests.exceptions import ReadTimeout,HTTPError,RequestException
try:
    response = requests.get('http://www.baidu.com',timeout=0.5)
    print(response.status_code)
except ReadTimeout:
    print('timeout')
except HTTPError:
    print('httperror')
except RequestException:
    print('reqerror')

HTTPError：如果 HTTP 请求返回了不成功的状态码

Timeout：请求超时

ConnectionError：遇到网络问题（如：DNS 查询失败、拒绝连接等）

TooManyRedirects：若请求超过了设定的最大重定向次数

RequestException：所有的requerst 异常

• requests登陆的几种方法

#通过账号和密码登陆

loginurl='https://xxxxx.com/check'  
formData={'username':'*****',  
          'password':'*****'}  
headers={'User-Agent':'Mozilla/5.0 (Windows NT 6.1; WOW64; rv:9.0.1) Gecko/20100101 Firefox/52.0'}  
res=req.post(loginurl,data=formData,headers=headers) 

#通过COOKIES

raw_cookies="k1=v1; k2=v2; k3=v3; 
cookies={}  
for line in raw_cookies.split(';'):  
      key,value=line.split('=',1)  
      cookies[key]=value  
loginurl='http://xxxxxx.com'  
res=req.post(loginurl,cookies=cookies)  
print res.content  
"访问其它的页面"  
logi1="http://xxxxx.htm"  
print req.post(logi1,cookies=cookies).content  

#通过session

import requests as req  
s=req.Session()  
param={'username':'****',  
       'password':'***'}  
url='https://xxxxxx'  
r=s.post(url,data=param,verify=False)  #登录获取登录后的session  
print r.content  
print s.get('http://xxxxxxx',verify=False).content  #通过session访问其它url