python之requests模块

1.安装

　　pip install requests

2.基本用法

　　就是以某种HTTP方法向远端服务器发送一个请求而已

 import requests

 r = requests.get('https://github.com/timeline.json')
 r = requests.post("http://httpbin.org/post")
 r = requests.put("http://httpbin.org/put")
 r = requests.delete("http://httpbin.org/delete")
 r = requests.head("http://httpbin.org/get")
 r = requests.options("http://httpbin.org/get")

　　所谓 requests.get，就是以GET方式发送一个REQUEST，得到一个Response类的结果，保存为 r。

3.URL传参/获取请求的URL

　　<协议>://<域名>/<接口>?<键1>=<值1>&<键2>=<值2>

　　requests库提供的HTTP方法，提供了名为params的参数，这个参数可接受一个python字典，并自动格式化为上述格式

 import requests

 url = 'http://www.so.com/s'

 params = {'ie': 'utf-8', 'q': 'query'}

 r = requests.get(url, params=params)

 print r.url

　　得到结果：

http://www.so.com/s?q=query&ie=utf-8

4.设置超时

　　requests的超时设置以秒为单位

　　设置超时为5秒

 import requests

 url = 'http://www.zhihu.com'

 r = requests.get(url, timeout=5)

5.请求头部

　　默认头部

 import requests

 cs_url = 'http://httpbin.org/get'
 r = requests.get (cs_url)
 print r.content

　　结果

{
  "args": {},
  "headers": {
    "Accept": "*/*",
    "Accept-Encoding": "gzip, deflate",
    "Host": "httpbin.org",
    "User-Agent": "python-requests/2.7.0 CPython/2.7.10 Windows/7"
  },
  "origin": "xx.xx.xx.xx",
  "url": "http://httpbin.org/get"
}

　　我们可以自定义请求的头部

 import requests

 my_headers = {'User-Agent' : 'From Liam Huang', 'Accept-Encoding' : 'gzip'}
 cs_url = 'http://httpbin.org/get'
 r = requests.get (cs_url, headers = my_headers)
 print r.content

　　结果

{
  "args": {},
  "headers": {
    "Accept": "*/*",
    "Accept-Encoding": "gzip",
    "Host": "httpbin.org",
    "User-Agent": "From Liam Huang"
  },
  "origin": "xx.xx.xx.xx",
  "url": "http://httpbin.org/get"
}

　　可以看到User-Agent和Accept-Encoding都已经改变

6.响应头部

　　可以通过response.headers来查看

 import requests

 cs_url = 'http://httpbin.org/get'
 r = requests.get (cs_url)
 print r.headers

　　结果

{
    "content-length": "",
    "server": "nginx",
    "connection": "keep-alive",
    "access-control-allow-credentials": "true",
    "date": "Fri, 26 Feb 2016 10:26:17 GMT",
    "access-control-allow-origin": "*",
    "content-type": "application/json"
}