Python标准库中用来处理HTTP的模块是urllib2，不过其中的API太零碎了，requests是更简单更人性化的第三方库。
用pip下载：
pip install requests
或者git：
git clone git://github.com/kennethreitz/requests.git
GET方法
>>> import requests >>> r = requests.get(‘https://api.github.com/events‘)
POST方法：
>>> r = requests.post("http://httpbin.org/post")
也可以使用其它方法：
>>> 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")
也可以将请求方法放在参数中：
>>> import requests >>> req = requests.request(‘GET‘, ‘http://httpbin.org/get‘)
1.如果要将参数放在url中传递，使用params参数，可以是字典或者字符串：
>>> payload = {‘key1‘: ‘value1‘, ‘key2‘: ‘value2‘}
>>> r = requests.get("http://httpbin.org/get", params=payload)
>>> r.url
u‘http://httpbin.org/get?key2=value2&key1=value1‘
2.如果要将参数放在request body中传递，使用data参数，可以是字典，字符串或者是类文件对象。
使用字典时将发送form-encoded data：
>>> payload = {‘key1‘: ‘value1‘, ‘key2‘: ‘value2‘}
>>> r = requests.post("http://httpbin.org/post", data=payload)
>>> print(r.text)
{
...
"form": {
"key2": "value2",
"key1": "value1"
},
...
}
使用字符串时将直接发送数据：
>>> import json
>>> url = ‘https://api.github.com/some/endpoint‘
>>> payload = {‘some‘: ‘data‘}
>>> r = requests.post(url, data=json.dumps(payload))
3.如果要上传文件，可以使用file参数发送Multipart-encoded数据，file参数是{ ‘name‘: file-like-objects}格式的字典 (or {‘name‘:(‘filename‘, fileobj)}) ：
>>> url = ‘http://httpbin.org/post‘
>>> files = {‘file‘: open(‘report.xls‘, ‘rb‘)}
>>> r = requests.post(url, files=files)
>>> r.text
{
...
"files": {
"file": "<censored...binary...data>"
},
...
}
也可以明确设置filename, content_type and headers：
>>> url = ‘http://httpbin.org/post‘
>>> files = {‘file‘: (‘report.xls‘, open(‘report.xls‘, ‘rb‘), ‘application/vnd.ms-excel‘, {‘Expires‘: ‘0‘})}
>>> r = requests.post(url, files=files)
>>> print r.text
{
"args": {},
"data": "",
"files": {
"file": "1\t2\r\n"
},
"form": {},
"headers": {
"Content-Type": "multipart/form-data; boundary=e0f9ff1303b841498ae53a903f27e565",
"Host": "httpbin.org",
"User-Agent": "python-requests/2.2.1 CPython/2.7.3 Windows/7",
},
"url": "http://httpbin.org/post"
}
>>> import json
>>> url = ‘https://api.github.com/some/endpoint‘
>>> payload = {‘some‘: ‘data‘}
>>> headers = {‘content-type‘: ‘application/json‘}
>>> r = requests.post(url, data=json.dumps(payload), headers=headers)
获取unicode字符串，会自动根据响应头部的字符编码(r.encoding)进行解码，当然也可以自己设定r.encoding：
>>> r = requests.get(‘https://github.com/timeline.json‘)
>>> r.text
u‘{"message":"Hello there, wayfaring stranger...
获取bytes字符串，会自动解码gzip和deflate数据：
>>> r.content
‘{"message":"Hello there, wayfaring stranger. ..
要存储web图片，可以：
>>> from PIL import Image >>> from StringIO import StringIO >>> i = Image.open(StringIO(r.content))
可以解码json对象：
>>> r.json()
{u‘documentation_url‘: u‘https://developer...
返回raw response，需要在requests请求中将stream设为True：
>>> r = requests.get(‘https://github.com/timeline.json‘, stream=True) >>> r.raw <requests.packages.urllib3.response.HTTPResponse object at 0x101194810> >>> r.raw.read(10) ‘\x1f\x8b\x08\x00\x00\x00\x00\x00\x00\x03‘
当然，更好的方法是迭代的处理数据：
with open(filename, ‘wb‘) as fd:
for chunk in r.iter_content(chunk_size):
fd.write(chunk)
获取响应代码：
>>> r = requests.get(‘http://httpbin.org/get‘) >>> r.status_code 200
获取响应headers：
>>> r.headers
{
‘content-encoding‘: ‘gzip‘,
‘transfer-encoding‘: ‘chunked‘,
‘connection‘: ‘close‘,
‘server‘: ‘nginx/1.0.4‘,
‘x-runtime‘: ‘148ms‘,
‘etag‘: ‘"e1ca502697e5c9317743dc078f67693f"‘,
‘content-type‘: ‘application/json‘
}
获取cookie，返回CookieJar对象：
>>> url = ‘http://www.baidu.com‘ >>> r = requests.get(url) >>> r.cookies
将CookieJar转为字典：
>>> requests.utils.dict_from_cookiejar(r.cookies)
{‘BAIDUID‘: ‘84722199DF8EDC372D549EC56CA1A0E2:FG=1‘, ‘BD_HOME‘: ‘0‘, ‘BDSVRTM‘: ‘0‘}
将字典转为CookieJar：
requests.utils.cookiejar_from_dict(cookie_dict, cookiejar=None, overwrite=True)
上传自己设置的cookie，使用cookies参数，可以是字典或者CookieJar对象：
>>> url = ‘http://httpbin.org/cookies‘
>>> cookies = dict(cookies_are=‘working‘)
>>> r = requests.get(url, cookies=cookies)
>>> r.text
‘{"cookies": {"cookies_are": "working"}}‘
如果需要在会话中保留cookie，需要用到后面要说的Session。
可以用history属性来追踪redirection
>>> r = requests.get(‘http://github.com‘) >>> r.url ‘https://github.com/‘ >>> r.status_code 200 >>> r.history [<Response [301]>]
要在会话中保留状态，可以使用request.Session()。
Session可以使用get，post等方法，返回的cookie等会在下一次访问时自动保留：
>>> import requests >>> s = requests.Session() >>> s.get(‘http://httpbin.org/get‘) 200
也可以自己设置headers，cookies：
>>> import requests
>>> s = requests.Session()
>>> s.headers={...}
Basic Authentication
>>> from requests.auth import HTTPBasicAuth >>> requests.get(‘https://api.github.com/user‘, auth=HTTPBasicAuth(‘user‘, ‘pass‘)) <Response [200]>
因为HTTP Basic Auth很常用，所以也可以直接验证：
>>> requests.get(‘https://api.github.com/user‘, auth=(‘user‘, ‘pass‘)) <Response [200]>
Digest Authentication
>>> from requests.auth import HTTPDigestAuth >>> url = ‘http://httpbin.org/digest-auth/auth/user/pass‘ >>> requests.get(url, auth=HTTPDigestAuth(‘user‘, ‘pass‘)) <Response [200]>
OAuth 1 Authentication
>>> import requests
>>> from requests_oauthlib import OAuth1
>>> url = ‘https://api.twitter.com/1.1/account/verify_credentials.json‘
>>> auth = OAuth1(‘YOUR_APP_KEY‘, ‘YOUR_APP_SECRET‘,
‘USER_OAUTH_TOKEN‘, ‘USER_OAUTH_TOKEN_SECRET‘)
>>> requests.get(url, auth=auth)
<Response [200]>
也可以使用自己写的验证类。比如某个web服务接受将X-Pizza报头设置成密码的验证，可以这样写验证类：
from requests.auth import AuthBase
class PizzaAuth(AuthBase):
"""Attaches HTTP Pizza Authentication to the given Request object."""
def __init__(self, username):
# setup any auth-related data here
self.username = username
def __call__(self, r):
# modify and return the request
r.headers[‘X-Pizza‘] = self.username
return r
使用：
>>> requests.get(‘http://pizzabin.org/admin‘, auth=PizzaAuth(‘kenneth‘)) <Response [200]>
使用代理：
import requests
proxies = {
"http": "http://10.10.1.10:3128",
"https": "http://10.10.1.10:1080",
}
requests.get("http://example.org", proxies=proxies)
可以设置环境变量：
$ 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")
如果代理需要验证：
proxies = {
"http": "http://user:pass@10.10.1.10:3128/",
}
Python Requests库：HTTP for Humans
原文：http://www.cnblogs.com/linxiyue/p/3980003.html