不建议自己用正则处理，基本所有的编程语言里都有json处理的库，比如在python中，可以这样做

 import json
import urllib2

data = json.load(urllib2.urlopen("https://api.github.com/users/defunkt"))

上面的代码 使用get请求github的api，当然也可以使用post方法，可以使用 requests 这个库，更加方便

结果

 {u'public_repos': 101, u'site_admin': True, u'subscriptions_url': u'https://api.github.com/users/defunkt/subscriptions', u'gravatar_id': u'b8dbb1987e8e5318584865f880036796', u'hireable': True, u'id': 2, u'followers_url': u'https://api.github.com/users/defunkt/followers', u'following_url': u'https://api.github.com/users/defunkt/following{/other_user}', u'blog': u'http://chriswanstrath.com/', u'followers': 12921, u'location': u'San Francisco', u'type': u'User', u'email': u'[email protected]', u'bio': u'', u'gists_url': u'https://api.github.com/users/defunkt/gists{/gist_id}', u'company': u'GitHub', u'events_url': u'https://api.github.com/users/defunkt/events{/privacy}', u'html_url': u'https://github.com/defunkt', u'updated_at': u'2013-12-22T08:59:46Z', u'received_events_url': u'https://api.github.com/users/defunkt/received_events', u'starred_url': u'https://api.github.com/users/defunkt/starred{/owner}{/repo}', u'public_gists': 284, u'name': u'Chris Wanstrath', u'organizations_url': u'https://api.github.com/users/defunkt/orgs', u'url': u'https://api.github.com/users/defunkt', u'created_at': u'2007-10-20T05:24:19Z', u'avatar_url': u'https://gravatar.com/avatar/b8dbb1987e8e5318584865f880036796?d=https%3A%2F%2Fidenticons.github.com%2Fc81e728d9d4c2f636f067f89cc14862c.png&r=x', u'repos_url': u'https://api.github.com/users/defunkt/repos', u'following': 208, u'login': u'defunkt'}
>>> data["login"]
u'defunkt'
>>>

如果使用requests模块

 >>> payload = {'key1': 'value1', 'key2': 'value2'}
>>> r = requests.post("http://httpbin.org/post", data=payload)
>>> print r.text
{
  ...
  "form": {
    "key2": "value2",
    "key1": "value1"
  },
  ...
}

顺便说下 http://httpbin.org 这个网站可以用来测试，非常方便

json 模块 http://docs.python.org/library/json.html
urilib 模块 http://docs.python.org/2/library/urllib.html
requests http://docs.python-requests.org/en/latest/user/quickstart/