对于目前众多的验证码解决方案来说，这个API有着中国电信这个重量级的运营商为靠山，应该是比较靠谱的了，而且还是免费的。详细情况请参阅：http://open.189.cn

使用方式：
#定义app_id和app_secret
r = RandCode('app_id', 'app_secret')
#支持平台的两种接口方式
#方式1：自定义接收验证码的回调URL
r.send('phone number', 'http://yourdomain/rand_code.php', '3')
#方式2：自定义验证码内容
r.send_sms('phone number', 189189)

复制代码 代码如下:
#!/usr/bin/env python
# coding: utf-8

from time import strftime, localtime
import urllib, urllib2, json
import hmac, hashlib

class RandCode(object):

 APP_ID = ''
 APP_SECRET = ''
 ACCESS_TOKEN = ''
 RANDCODE_TOKEN = ''
 TOKEN_API = 'https://oauth.api.189.cn/emp/oauth2/v2/access_token'
 RANDCODE_TOKEN_API = 'http://api.189.cn/v2/dm/randcode/token'
 RANDCODE_SEND_API = 'http://api.189.cn/v2/dm/randcode/send'
 RANDCODE_SENDSMS_API = 'http://api.189.cn/v2/dm/randcode/sendSms'

 def __init__(self, app_id='', app_secret='', access_token=''):
  self.APP_ID = app_id or RandCode.APP_ID
  self.APP_SECRET = app_secret or RandCode.APP_SECRET
  self.ACCESS_TOKEN = access_token or self.__fetch_access_token()
  self.RANDCODE_TOKEN = self.__fetch_randcode_token()

 def send(self, phone, url, exp_time):
  result = False
  if self.ACCESS_TOKEN and self.RANDCODE_TOKEN:
   data = {
    'app_id':self.APP_ID,
    'access_token':self.ACCESS_TOKEN,
    'token':self.RANDCODE_TOKEN,
    'phone':phone,
    'url':url,
    'exp_time':exp_time,
    'timestamp':self.__date_time(),
    }
   data = self.__build_request_string(data)
   data = self.__data_sign(data)
   if data:
    res = self.__request_data('post', data, self.RANDCODE_SEND_API)
    json_data = json.loads(res)
    if json_data['res_code'] == 0:
     result = True
  return result

 def send_sms(self, phone, randcode, exp_time='2'):
  result = False
  if self.ACCESS_TOKEN and self.RANDCODE_TOKEN:
   data = {
    'app_id':self.APP_ID,
    'access_token':self.ACCESS_TOKEN,
    'token':self.RANDCODE_TOKEN,
    'phone':phone,
    'randcode':str(randcode),
    'exp_time':exp_time,
    'timestamp':self.__date_time(),
    }
   data = self.__build_request_string(data)
   data = self.__data_sign(data)
   if data:
    res = self.__request_data('post', data, self.RANDCODE_SENDSMS_API)
    json_data = json.loads(res)
    if json_data['res_code'] == 0:
     result = True
  return result
  pass

 def __request_data(self, method, data, url):
  if isinstance(data, dict):
   data = urllib.urlencode(data)
  if method == 'post':
   req = urllib2.Request(url, data)
  else:
   url = '%s?%s' % (url, data)
   req = urllib2.Request(url)
  return urllib2.urlopen(req).read()

 def __fetch_access_token(self):
  access_token = self.ACCESS_TOKEN
  if access_token == '':
   data = {
    'grant_type':'client_credentials',
    'app_id':self.APP_ID,
    'app_secret':self.APP_SECRET,
    }
   res = self.__request_data('post', data, self.TOKEN_API)
   json_data = json.loads(res)
   if json_data['res_code'] == '0':
    access_token = json_data['access_token']
   else:
    raise ValueError(json_data['res_message'])
  return access_token

 def __fetch_randcode_token(self):
  result = ''
  if self.ACCESS_TOKEN != '':
   data = {
    'app_id':self.APP_ID,
    'access_token':self.ACCESS_TOKEN,
    'timestamp':self.__date_time(),
    }
   data = self.__build_request_string(data)
   data = self.__data_sign(data)
   if data:
    res = self.__request_data('get', data, self.RANDCODE_TOKEN_API)
    json_data = json.loads(res)
    if json_data['res_code'] == 0:
     result = json_data['token']
    else:
     raise ValueError(json_data['res_message'])
  return result

 def __data_sign(self, data):
  result = ''
  if data:
   if isinstance(data, dict):
    data = self.__build_request_string(data)
    sign = hmac.new(self.APP_SECRET, urllib.urlencode(data), hashlib.sha1).digest()
   elif isinstance(data, unicode):
    sign = hmac.new(self.APP_SECRET, data, hashlib.sha1).digest()
   if data:
    result = "%s&sign=%s" % ( data, urllib.quote(sign.encode('base64').strip()) )
  return result

 def __build_request_string(self, dict):
  keys = dict.keys()
  keys.sort()
  return '&'.join([ key + "=" + dict[key] for key in keys ])

 def __date_time(self):
  return strftime("%Y-%m-%d %H:%M:%S", localtime())

if __name__  == '__main__':
 r = RandCode('app_id', 'app_secret')
 r.send('phone number', 'http://yourdomain/rand_code.php', '3')
 r.send_sms('phone number', 189189)