Python用法速查@HTTP

Requests：HTTP for humans

HTTP请求

Requests 中HTTP请求的6种方法

import requests

r = requests.get("http://httpbin.org/get") # get 访问资源
r = requests.post("http://httpbin.org/post") # post 修改部分资源
r = requests.put("http://httpbin.org/put") # put 按唯一标识修改整个资源
r = requests.delete("http://httpbin.org/delete") # delete 删除指定唯一标识资源
r = requests.head("http://httpbin.org/get") # head 返回资源信息，而不是资源本身
r = requests.options("http://httpbin.org/get") #options 返回资源支持的所有请求方式

GET params

用dict表示参数

import requests

payload = {'page': '1', 'per_page': '10'}
r = requests.get("http://httpbin.org/get", params=payload)

>>>r.url 
'http://httpbin.org/get?page=1&per_page=10' #自动编码后的URL 
>>>r.status_code)
200  #状态码 
>>>r.text #服务器响应返回的原数据
{
  "args": {}, 
  "headers": {
    "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8", 
    "Accept-Encoding": "gzip, deflate", 
    "Accept-Language": "zh-CN,zh;q=0.8,zh-TW;q=0.7,zh-HK;q=0.5,en-US;q=0.3,en;q=0.2", 
    "Host": "httpbin.org", 
    "Upgrade-Insecure-Requests": "1", 
    "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:90.0) Gecko/20100101 Firefox/90.0", 
    "X-Amzn-Trace-Id": "Root=1-61069277-63437d5e5d48a6ec102f8b92"
  }, 
  "origin": "39.149.82.108", 
  "url": "http://httpbin.org/get"
}

POST data/json

以表单形式传递

import requests

payload = {'page': 1, 'per_page': 10}
r = requests.post("http://httpbin.org/post", data=payload)

>>>r.text
{
  "args": {}, 
  "data": "", 
  "files": {}, 
  "form": {
    "page": "1", 
    "per_page": "10"
  }, 
  "headers": {
    "Accept": "*/*", 
    "Accept-Encoding": "gzip, deflate", 
    "Content-Length": "18", 
    "Content-Type": "application/x-www-form-urlencoded", 
    "Host": "httpbin.org", 
    "User-Agent": "python-requests/2.25.0", 
    "X-Amzn-Trace-Id": "Root=1-61069443-38e30b8e7490c5eb75b60c0f"
  }, 
  "json": null, 
  "origin": "36.229.102.208", 
  "url": "http://httpbin.org/post"
}

用json形式传递
编码后传递

import json
import requests

payload = {'page': 1, 'per_page': 10}
r = requests.post("http://httpbin.org/post", data=json.dumps(payload))

直接json

import requests

payload = {'page': 1, 'per_page': 10}
r = requests.post("http://httpbin.org/post", json=payload)

这两种做法是等价的

headers

import requests

url = 'http://httpbin.org/post'
payload = {'page': 1, 'per_page': 10}
headers = {'User-Agent': 'Mozilla/4.0 (compatible; MSIE 5.5; Windows NT)'}# 修改HTTP头部

r = requests.post("http://httpbin.org/post", json=payload, headers=headers)

>>>r.request.headers #查看请求的头部
>>>r.headers #查看服务器返回的头部

HTTP响应

对于响应的状态码，我们用r.status_code访问
对于响应的正文我们有多种方式读取

r.text 普通

读取unicode形式响应

import requests

r = requests.get("https://github.com/timeline.json")
print r.text
print r.encoding

# 输出
{"message":"Hello there, wayfaring stranger. If you’re reading this then you probably didn’t see our blog post a couple of years back announcing that this API would go away: http://git.io/17AROg Fear not, you should be able to get what you need from the shiny new Events API instead.","documentation_url":"https://developer.github.com/v3/activity/events/#list-public-events"}
utf-8

r.json() JSON

读取json形式响应,并解析成python的对象

import requests

r = requests.get("https://github.com/timeline.json")

if r.status_code == 200:
    print r.headers.get('content-type')
    print r.json()
    
# 输出
application/json; charset=utf-8
{u'documentation_url': u'https://developer.github.com/v3/activity/events/#list-public-events', u'message': u'Hello there, wayfaring stranger. If youu2019re reading this then you probably didnu2019t see our blog post a couple of years back announcing that this API would go away: http://git.io/17AROg Fear not, you should be able to get what you need from the shiny new Events API instead.'}

r.content 二进制

以字节方式访问响应数据

import requests

url = 'https://github.com/reactjs/redux/blob/master/logo/logo.png?raw=true'
r = requests.get(url)
image_data = r.content   # 获取二进制数据

with open('/Users/Ethan/Downloads/redux.png', 'wb') as fout:
    fout.write(image_data)

r.raw 原始

获取原始的套字节响应

import requests

url = 'https://github.com/reactjs/redux/blob/master/logo/logo.png?raw=true'
r = requests.get(url, stream=True)
print r.raw
r.raw.read(10)

# 输出
<requests.packages.urllib3.response.HTTPResponse object at 0x1113b0a90>
'x89PNG
x1a
x00x00'

r.history 重定向

r.history 是一个响应列表

>>> import requests

>>> headers = {'User-Agent': 'Mozilla/4.0 (compatible; MSIE 5.5; Windows NT)'}
>>> r = requests.get('https://toutiao.io/k/c32y51', headers=headers)

>>> r.status_code
200

>>> r.url   # 发生了重定向，响应对象的 url，跟请求对象不一样
u'http://www.jianshu.com/p/490441391db6?hmsr=toutiao.io&utm_medium=toutiao.io&utm_source=toutiao.io'

>>> r.history
[<Response [302]>]

>>> r.history[0].text
u'<html><body>You are being <a href="http://www.jianshu.com/p/490441391db6?hmsr=toutiao.io&amp;utm_medium=toutiao.io&amp;utm_source=toutiao.io">redirected</a>.</body></html>'

allow_redirects=False 禁止重定向

>>> import requests

>>> headers = {'User-Agent': 'Mozilla/4.0 (compatible; MSIE 5.5; Windows NT)'}
>>> r = requests.get('https://toutiao.io/k/c32y51', headers=headers, allow_redirects=False)
>>> r.url    # 禁止重定向，响应对象的 url 跟请求对象一致
u'https://toutiao.io/k/c32y51'
>>> r.history
[]
>>> r.text
u'<html><body>You are being <a href="http://www.jianshu.com/p/490441391db6?hmsr=toutiao.io&amp;utm_medium=toutiao.io&amp;utm_source=toutiao.io">redirected</a>.</body></html>'

Cookie

cookies=cookies发送cookie到服务器

>>> import requests

>>> url = 'http://httpbin.org/cookies'
>>> cookies = dict(key1='value1')

>>> r = requests.get(url, cookies=cookies)
>>> r.text
u'{
  "cookies": {
    "key1": "value1"
  }
}
'
>>> print r.text
{
  "cookies": {
    "key1": "value1"
  }
}

r.cookies['some_key']读取响应cookie

>>> import requests

>>> url = 'http://exmaple.com/some/cookie/setting/url'
>>> r = requests.get(url)

>>> r.cookies['some_key']
'some_value'

requests.Session() 会话对象

夸请求保持cookie

>>> import requests
>>> s = requests.Session()
>>> s.get('http://httpbin.org/cookies/set/sessioncookie/123456789')
<Response [200]>
>>> r = s.get("http://httpbin.org/cookies")
>>> print r.text
{
  "cookies": {
    "sessioncookie": "123456789"
  }
}

为请求方提供缺省数据

import requests

s = requests.Session()
s.auth = ('user', 'pass')
s.headers.update({'x-test': 'true'})

# x-test 和 x-test2 都会被发送
s.get('http://httpbin.org/headers', headers={'x-test2': 'true'})

HTTP代理 proxies=proxies

为任意请求设置HTTP代理

import requests

proxies = {
  "http": "http://10.10.1.10:3128",
  "https": "http://10.10.1.10:1080",
}

requests.get("http://example.org", proxies=proxies)

通过设置环境变量 HTTP_PROXY=host:port 和 HTTPS_PROXY=host:port 来配置代理

$ export HTTP_PROXY="http://10.10.1.10:3128"
$ export HTTPS_PROXY="http://10.10.1.10:1080"

$ python
>>> import requests
>>> requests.get("http://example.org")

SOCKS代理

需装第三方库pip install requests[socks]

import requests

proxies = {
  "http": "socks5://user:pass@host:port",
  "https": "socks5://user:pass@host:port",
}

requests.get("http://example.org", proxies=proxies)

身份认证

Basic Auth 基本身份认证

>>> from requests.auth import HTTPBasicAuth
>>> requests.get('https://api.github.com/user', auth=HTTPBasicAuth('user', 'pass'))
或
requests.get('https://api.github.com/user', auth=('user', 'pass'))

OAuth 2 认证

Web API认证方式，配合requests-oauthlib库使用

>>> # Credentials you get from registering a new application
>>> client_id = '<the id you get from github>'
>>> client_secret = '<the secret you get from github>'

>>> # OAuth endpoints given in the GitHub API documentation
>>> authorization_base_url = 'https://github.com/login/oauth/authorize'
>>> token_url = 'https://github.com/login/oauth/access_token'

>>> from requests_oauthlib import OAuth2Session
>>> github = OAuth2Session(client_id)

>>> # Redirect user to GitHub for authorization
>>> authorization_url, state = github.authorization_url(authorization_base_url)
>>> print 'Please go here and authorize,', authorization_url

>>> # Get the authorization verifier code from the callback url
>>> redirect_response = raw_input('Paste the full redirect URL here:')

>>> # Fetch the access token
>>> github.fetch_token(token_url, client_secret=client_secret,
>>>         authorization_response=redirect_response)

>>> # Fetch a protected resource, i.e. user profile
>>> r = github.get('https://api.github.com/user')
>>> print r.content

参考

explore-python/HTTP/Requests