Python requests库的使用（一）

requests库官方使用手册地址：http://www.python-requests.org/en/master/；中文使用手册地址：http://cn.python-requests.org/zh_CN/latest/；

requests库作者Kenneth Reitz个人主页：https://www.kennethreitz.org/；

requests库github地址：https://github.com/requests/requests；

requests库下载方法：pip install requests

学习目的：Python+requests库实现接口自动化测试；

requests库作者Kenneth Reitz创建的server端：http://httpbin.org/；可以学习时使用。

python自带的接口测试的库urllib、urllib2、urllib3，这三个库不是进阶关系，是彼此独立的。requests库使用了urllib3（多次请求重复使用一个socket，消耗更少的资源）。

1.使用urllib、urllib2实现的一个小程序：

# -*- coding: utf-8 -*-
import urllib
import urllib2        #引入urllib、urllib2库

URL_IP = 'http://httpbin.org/ip'
URL_GET = 'http://httpbin.org/get'

def use_simple_urllib2():
    response = urllib2.urlopen(URL_IP)       #urlopen() 访问url的方法
    print '>>>>Response Headers:'
    print response.info()                                #info() 打印headers的方法
    print '>>>>Response body:'
    print ''.join([line for line in response.readlines()])    #join() 将response body中的元素以"连接生成一个新的字符串 str = "-"; seq = ("a", "b", "c"); print str.join( seq );      结果：a-b-c

                                                                                                                                                                                       
def use_params_urllib2():
    #构建请求参数

params = urllib.urlencode({'param1': 'hello', 'param2': 'world'})      #urlencode() 将参数进行url编码
    #发送请求

response = urllib2.urlopen('?'.join([URL_GET, '%s']) % params)  
    #处理响应

print '>>>>Response Headers:'
    print response.info()
    print '>>>>Status Code:'
    print response.getcode()          #getcode()获取status code的方法 
    print '>>>>Request body:'
    print ''.join([line for line in response.readlines()])

if __name__ == '__main__':
    print '>>>Use simple urllib2:'
    use_simple_urllib2()
    print ''
    print '>>>Use params urllib2:'
    use_params_urllib2()

服务器返回的数据：

C:\Python27\python.exe C:/Users/lxz/Desktop/study/AndroidAppshizhandaima/HttpApi/jiekouceshi.py
>>>Use simple urllib2:
>>>>Response Headers:
Connection: close                 #可以看到，一次请求后connection的状态是close，说明urllib库每次都要重新打开一个socket
Server: meinheld/0.6.1
Date: Fri, 18 Aug 2017 06:25:44 GMT
Content-Type: application/json
Access-Control-Allow-Origin: *
Access-Control-Allow-Credentials: true
X-Powered-By: Flask
X-Processed-Time: 0.000429153442383
Content-Length: 32
Via: 1.1 vegur

>>>>Response body:
{
  "origin": "39.109.125.70"
}

>>>Use params urllib2:
>>>>Response Headers:
Connection: close
Server: meinheld/0.6.1
Date: Fri, 18 Aug 2017 06:25:44 GMT
Content-Type: application/json
Access-Control-Allow-Origin: *
Access-Control-Allow-Credentials: true
X-Powered-By: Flask
X-Processed-Time: 0.000815868377686
Content-Length: 309
Via: 1.1 vegur

>>>>Status Code:
200
>>>>Request body:
{
  "args": {
    "param1": "hello",
    "param2": "world"
  },
  "headers": {
    "Accept-Encoding": "identity",
    "Connection": "close",
    "Host": "httpbin.org",
    "User-Agent": "Python-urllib/2.7"
  },
  "origin": "39.109.125.70",
  "url": "http://httpbin.org/get?param2=world&param1=hello"
}

2.使用requests实现的一个小程序：

#coding=utf-8
import requests        #引入requests库

URL_IP = 'http://httpbin.org/ip'
URL_GET = 'http://httpbin.org/get'

def use_simple_requests():
    response = requests.get(URL_IP)      #以get方法访问url
    print '>>>>Response Headers:'
    print response.headers                     # .headers 获取headers
    print '>>>>Response body:'
    print response.text                             # .text 获取值

def use_params_requests():
    params = {'param1': 'hello', 'param2': 'world'}         #参数直接以字典的形式赋值，不需要编码
    #发送请求
    response = requests.get(URL_GET, params=params)    #get方法会自动连接url和参数
    #处理响应
    print '>>>>Response Headers:'
    print response.headers
    print '>>>>Status Code:'
    print response.status_code         # .status_code 获取status_code方法
    print '>>>>Reason:'
    print response.reason                 # .reason 获取访问接口结果方法
    print '>>>>Request body:'
    print response.text                        # .text 获取值

if __name__ == '__main__':
    print '>>>Use simple requests:'
    use_simple_requests()
    print ''
    print '>>>Use params requests:'
    use_params_requests()

服务器返回的数据：

>>>Use simple requests:
>>>>Response Headers:
{'Content-Length': '34', 'X-Processed-Time': '0.000436067581177', 'X-Powered-By': 'Flask', 'Server': 'meinheld/0.6.1', 'Connection': 'keep-alive', 'Via': '1.1 vegur', 'Access-Control-Allow-Credentials': 'true', 'Date': 'Sat, 19 Aug 2017 08:12:17 GMT', 'Access-Control-Allow-Origin': '*', 'Content-Type': 'application/json'}
>>>>Response body:
{
  "origin": "111.204.108.132"
}

>>>Use params requests:
>>>>Response Headers:
{'Content-Length': '343', 'X-Processed-Time': '0.000698089599609', 'X-Powered-By': 'Flask', 'Server': 'meinheld/0.6.1', 'Connection': 'keep-alive', 'Via': '1.1 vegur', 'Access-Control-Allow-Credentials': 'true', 'Date': 'Sat, 19 Aug 2017 08:12:18 GMT', 'Access-Control-Allow-Origin': '*', 'Content-Type': 'application/json'}

#可以看到使用requests库，connection的状态是keep-alive，这就说明了多次请求重复使用一个socket，所以相比urllib库，requests库会消耗更少的资源

>>>>Status Code:
200
>>>>Reason:
OK
>>>>Request body:
{
  "args": {
    "param1": "hello",
    "param2": "world"
  },
  "headers": {
    "Accept": "*/*",
    "Accept-Encoding": "gzip, deflate",
    "Connection": "close",
    "Host": "httpbin.org",
    "User-Agent": "python-requests/2.18.3"
  },
  "origin": "111.204.108.132",
  "url": "http://httpbin.org/get?param2=world&param1=hello"
}

3.发送请求

请求方法：

使用requests库发送请求的方法：requests.[method](url)

PATCH：更新资源；通过提交json数据的方式实现，相比较PUT，PATCH更轻量级。

github上公共API的使用方法地址：https://developer.github.com/v3/

使用时调用URL：https://api.github.com                            #可以用来日常学习使用

下面的演示用代码都会用到以上两个域名。

3.1，获取用户名方法  https://developer.github.com/v3/users  

其中https://api.github.com是根域名，/users/username是endpoint。

github官网上返回数据的样例：

实现代码：

# -*- coding: utf-8 -*-
import json
import requests

URL = 'https://api.github.com'

def build_uri(endpoint):
    return '/'.join([URL, endpoint])

def better_print(json_str):
    return json.dumps(json.loads(json_str), indent=4)

def request_method():
    response = requests.get(build_uri('users/caolanmiao'))
    print better_print(response.text)

if __name__ == '__main__':
    request_method()

返回的数据：

{
    "public_repos": 0,
    "site_admin": false,
    "subscriptions_url": "https://api.github.com/users/caolanmiao/subscriptions",
    "gravatar_id": "",
    "hireable": null,
    "id": 22490616,
    "followers_url": "https://api.github.com/users/caolanmiao/followers",
    "following_url": "https://api.github.com/users/caolanmiao/following{/other_user}",
    "blog": "",
    "followers": 0,
    "location": "Pecking",
    "type": "User",
    "email": null,
    "bio": "Software QA Engineer",
    "gists_url": "https://api.github.com/users/caolanmiao/gists{/gist_id}",
    "company": null,
    "events_url": "https://api.github.com/users/caolanmiao/events{/privacy}",
    "html_url": "https://github.com/caolanmiao",
    "updated_at": "2017-08-19T09:27:39Z",
    "received_events_url": "https://api.github.com/users/caolanmiao/received_events",
    "starred_url": "https://api.github.com/users/caolanmiao/starred{/owner}{/repo}",
    "public_gists": 0,
    "name": "Yannan.Jia",
    "organizations_url": "https://api.github.com/users/caolanmiao/orgs",
    "url": "https://api.github.com/users/caolanmiao",
    "created_at": "2016-09-28T06:00:27Z",
    "avatar_url": "https://avatars0.githubusercontent.com/u/22490616?v=4",
    "repos_url": "https://api.github.com/users/caolanmiao/repos",
    "following": 1,
    "login": "caolanmiao"
}
返回的数据信息中就是我自己的github账号，说明这次请求成功了。

注意：对于github而言，传入参数auth=('用户名','密码')，既可以完成认证。

访问user/emails API，修改上述代码的以下部分，增加auth参数，完成认证

response = requests.get(build_uri('user/emails'),auth=('caolanmiao','########'))

返回数据：

[{"email":"jia#####@outlook.com","primary":true,"verified":true,"visibility":"public"}]
[
    {
        "verified": true,
        "email": "jia#####@outlook.com",
        "visibility": "public",
        "primary": true
    }
]
符合API使用说明。

3.2，带参数的请求

get方式：这种参数直接拼接在url后面的参数提交方式的优点是：信息传递/页面到页面的跳转方便；缺点：明文显示，安全性差、浏览器对url的长度有限制。

post方式：安全性强，可以传递大量参数。

1.get方式实现参数传递，测试用API地址：https://developer.github.com/v3/users

since参数会过滤掉在它之前的users（比如since为11，那么只显示11之后的users）

实现代码：

# -*- coding: utf-8 -*-
import json
import requests
from requests import exceptions

URL = 'https://api.github.com'

def build_uri(endpoint):
    return '/'.join([URL, endpoint])

def better_print(json_str):
    return json.dumps(json.loads(json_str), indent=4)

def params_request():
    response = requests.get(build_uri('users'), params={'since': 11})
    print better_print(response.text)
    print response.request.headers
    print response.url

if __name__ == '__main__':
    params_request()

2.post、patch方式实现参数传递，测试用API地址：https://developer.github.com/v3/users/emails/

实现代码：

def json_request():
    response = requests.patch(build_uri('user'), auth=('caolanmiao', '########'), json={'name': 'Yannan.Jia', 'email': 'helloworld1@ceshi.com'})
    response = requests.post(build_uri('user/emails'), auth=('caolanmiao', '########'), json=['helloworld2@ceshi.com'])
    print better_print(response.text)
    print response.request.headers
    print response.request.body
    print response.status_code

通过Patch方法，修改名称和邮箱；通过Post增加邮箱；