python的requests初步使用

http://www.yangyanxing.com/?p=1079

早就听说requests的库的强大，只是还没有接触，今天接触了一下，发现以前使用urllib，urllib2等方法真是太搓了……
这里写些简单的使用初步作为一个记录
一、安装 http://cn.python-requests.org/en/latest/user/install.html#install 二、发送无参数的get请求

01	>>> r = requests.get('http://httpbin.org/get')

02	>>> print r.text

03

{

04	"args": {},

05	"headers": {

06	"Accept": "*/*",

07	"Accept-Encoding": "gzip, deflate",

08	"Connection": "close",

09	"Host": "httpbin.org",

10	"User-Agent": "python-requests/2.3.0 CPython/2.6.6 Windows/7",

11	"X-Request-Id": "8a28bbea-55cd-460b-bda3-f3427d66b700"

12

},

13	"origin": "124.192.129.84",

14	"url": "http://httpbin.org/get"

15

}

Code inserted with Steve Dunn's Windows Live Writer Code Formatter Plugin. http://dunnhq.com 三、发送带参数的get请求,将key与value放入一个字典中，通过params参数来传递,其作用相当于urllib.urlencode

1	>>> import requests

2	>>> pqyload = {'q':'杨彦星'}

3	>>> r = requests.get('http://www.so.com/s',params = pqyload)

4

>>> r.url

5	u'http://www.so.com/s?q=%E6%9D%A8%E5%BD%A6%E6%98%9F'

Code inserted with Steve Dunn's Windows Live Writer Code Formatter Plugin. http://dunnhq.com 四、发送post请求，通过data参数来传递,

01	>>> payload = {'a':'杨','b':'hello'}

02	>>> r = requests.post("http://httpbin.org/post", data=payload)

03	>>> print r.text

04

{

05	"args": {},

06	"data": "",

07	"files": {},

08

"form": {

09	"a": "u6768",

10	"b": "hello"

11

},

12	"headers": {

13	"Accept": "*/*",

14	"Accept-Encoding": "gzip, deflate",

15	"Connection": "close",

16	"Content-Length": "19",

17	"Content-Type": "application/x-www-form-urlencoded",

18	"Host": "httpbin.org",

19	"User-Agent": "python-requests/2.3.0 CPython/2.6.6 Windows/7",

20	"X-Request-Id": "c81cb937-04b8-4a2d-ba32-04b5c0b3ba98"

21

},

22	"json": null,

23	"origin": "124.192.129.84",

24	"url": "http://httpbin.org/post"

25

}

26

>>>

Code inserted with Steve Dunn's Windows Live Writer Code Formatter Plugin. http://dunnhq.com 可以看到，post参数已经传到了form里,data不光可以接受字典类型的数据，还可以接受json等格式

1	>>> payload = {'a':'杨','b':'hello'}

2	>>> import json

3	>>> r = requests.post('http://httpbin.org/post', data=json.dumps(payload))

Code inserted with Steve Dunn's Windows Live Writer Code Formatter Plugin. http://dunnhq.com 五、发送文件的post类型，这个相当于向网站上传一张图片，文档等操作，这时要使用files参数

1	>>> url = 'http://httpbin.org/post'

2	>>> files = {'file': open('touxiang.png', 'rb')}

3	>>> r = requests.post(url, files=files)

Code inserted with Steve Dunn's Windows Live Writer Code Formatter Plugin. http://dunnhq.com 5.1 定制headers，使用headers参数来传递

1	>>> import json

2	>>> url = 'https://api.github.com/some/endpoint'

3	>>> payload = {'some': 'data'}

4	>>> headers = {'content-type': 'application/json'}

5

6	>>> r = requests.post(url, data=json.dumps(payload), headers=headers)

Code inserted with Steve Dunn's Windows Live Writer Code Formatter Plugin. http://dunnhq.com
六、响应内容
6.1 响应状态码
r = requests.get('http://httpbin.org/get')
print r.status_code
6.2 响应头

1	>>> print r.headers

2	{'content-length': '519', 'server': 'gunicorn/18.0', 'connection': 'keep-alive', 'date': 'Sun, 15 Jun 2014 14:19:52 GMT', 'access-control-allow-origin': '*', 'content-type': 'application/json'}

Code inserted with Steve Dunn's Windows Live Writer Code Formatter Plugin. http://dunnhq.com 也可以取到这个个别的响应头用来做一些判断，这里的参数是不区分大小写的
r.headers[‘Content-Type’]
r.headers.get(‘Content-Type’)
6.3 响应内容，前面已经在应用了
r.text
r.content

七、获取响应中的cookies

1	>>> r = requests.get('http://www.baidu.com')

2	>>> r.cookies['BAIDUID']

3	'D5810267346AEFB0F25CB0D6D0E043E6:FG=1'

Code inserted with Steve Dunn's Windows Live Writer Code Formatter Plugin. http://dunnhq.com 也可以自已定义请求的COOKIES

01	>>> url = 'http://httpbin.org/cookies'

02	>>> cookies = {'cookies_are':'working'}

03	>>> r = requests.get(url,cookies = cookies)

04

>>>

05	>>> print r.text

06

{

07	"cookies": {

08	"cookies_are": "working"

09

}

10

}

11

>>>

Code inserted with Steve Dunn's Windows Live Writer Code Formatter Plugin. http://dunnhq.com cookies还有很多，因为目前我也还不是很多，以后再扩充吧
八、使用timeout参数设置超时时间
>>> requests.get('http://github.com', timeout=1)
<Response [200]>
如果将时间设置成非常小的数，如requests.get('http://github.com', timeout=0.001)，那么如果在timeout的时间内没有连接，那么将会抛出一个Timeout的异常
九、访问中使用session
先初始化一个session对象，s = requests.Session()
然后使用这个session对象来进行访问，r = s.post(url,data = user)

参考文章 http://blog.csdn.net/iloveyin/article/details/21444613 基本上都是从这扒的代码

以下通过访问人人网来获取首页中的最近来访问，然后再访问查看更多的来访来读取更多的最近来访
更多的来访就是以带session的访问http://www.renren.com/myfoot.do
view source

01	#coding:utf-8

02	import requests

03

import re

04

05	url = r'http://www.renren.com/ajaxLogin'

06

07	user = {'email':'email','password':'pass'}

08	s = requests.Session()

09	r = s.post(url,data = user)

10

11	html = r.text

12	visit = []

13	first = re.compile(r'</span><span class="time-tip first-tip"><span class="tip-content">(.*?)</span>')

14	second = re.compile(r'</span><span class="time-tip"><span class="tip-content">(.*?)</span>')

15	third = re.compile(r'</span><span class="time-tip last-second-tip"><span class="tip-content">(.*?)</span>')

16	last = re.compile(r'</span><span class="time-tip last-tip"><span class="tip-content">(.*?)</span>')

17	visit.extend(first.findall(html))

18	visit.extend(second.findall(html))

19	visit.extend(third.findall(html))

20	visit.extend(last.findall(html))

21	for i in visit:

22

print i

23

24	print '以下是更多的最近来访'

25	vm = s.get('http://www.renren.com/myfoot.do')

26	fm = re.compile(r'"name":"(.*?)"')

27	visitmore = fm.findall(vm.text)

28	for i in visitmore:

29

print i