如何通过python采用django框架实现支付宝即时到帐接口？

import types 
from urllib import urlencode, urlopen 
from hashcompat import md5_constructor as md5<span style="white-space:pre"> </span>#见hashcompact.py 
from config import settings<span style="white-space:pre">   </span>#见config.py 
 
#字符串编解码处理 
def smart_str(s, encoding='utf-8', strings_only=False, errors='strict'): 
 if strings_only and isinstance(s, (types.NoneType, int)): 
  return s 
 if not isinstance(s, basestring): 
  try: 
   return str(s) 
  except UnicodeEncodeError: 
   if isinstance(s, Exception): 
    return ' '.join([smart_str(arg, encoding, strings_only, 
      errors) for arg in s]) 
   return unicode(s).encode(encoding, errors) 
 elif isinstance(s, unicode): 
  return s.encode(encoding, errors) 
 elif s and encoding != 'utf-8': 
  return s.decode('utf-8', errors).encode(encoding, errors) 
 else: 
  return s 
 
# 网关地址 
_GATEWAY = 'https://mapi.alipay.com/gateway.do?' 
 
 
# 对数组排序并除去数组中的空值和签名参数 
# 返回数组和链接串 
def params_filter(params): 
 ks = params.keys() 
 ks.sort() 
 newparams = {} 
 prestr = '' 
 for k in ks: 
  v = params[k] 
  k = smart_str(k, settings.ALIPAY_INPUT_CHARSET) 
  if k not in ('sign','sign_type') and v != '': 
   newparams[k] = smart_str(v, settings.ALIPAY_INPUT_CHARSET) 
   prestr += '%s=%s&' % (k, newparams[k]) 
 prestr = prestr[:-1] 
 return newparams, prestr 
 
 
# 生成签名结果 
def build_mysign(prestr, key, sign_type = 'MD5'): 
 if sign_type == 'MD5': 
  return md5(prestr + key).hexdigest() 
 return '' 
 
 
# 即时到账交易接口 
def create_direct_pay_by_user(tn, subject, body, bank, total_fee): 
 params = {} 
 params['service']  = 'create_direct_pay_by_user' 
 params['payment_type'] = '1'  #商品购买，只能选这个 
  
 # 获取配置文件 
 params['partner']   = settings.ALIPAY_PARTNER 
 params['seller_id']   = settings.ALIPAY_PARTNER 
 params['seller_email']  = settings.ALIPAY_SELLER_EMAIL 
 params['return_url']  = settings.ALIPAY_RETURN_URL 
 params['notify_url']  = settings.ALIPAY_NOTIFY_URL 
 params['_input_charset'] = settings.ALIPAY_INPUT_CHARSET 
 params['show_url']   = settings.ALIPAY_SHOW_URL 
  
 # 从订单数据中动态获取到的必填参数 
 params['out_trade_no'] = tn  # 请与贵网站订单系统中的唯一订单号匹配 
 params['subject']  = subject # 订单名称，显示在支付宝收银台里的“商品名称”里，显示在支付宝的交易管理的“商品名称”的列表里。 
 params['body']   = body  # 订单描述、订单详细、订单备注，显示在支付宝收银台里的“商品描述”里，可以为空 
 params['total_fee']  = total_fee # 订单总金额，显示在支付宝收银台里的“应付总额”里，精确到小数点后两位 
  
 # 扩展功能参数——网银提前 
 if bank=='alipay' or bank=='': 
  params['paymethod'] = 'directPay' # 支付方式，四个值可选：bankPay(网银); cartoon(卡通); directPay(余额); CASH(网点支付) 
  params['defaultbank'] = ''   # 支付宝支付，这个为空 
 else: 
  params['paymethod'] = 'bankPay'  # 默认支付方式，四个值可选：bankPay(网银); cartoon(卡通); directPay(余额); CASH(网点支付) 
  params['defaultbank'] = bank  # 默认网银代号，代号列表见http://club.alipay.com/read.php?tid=8681379   
  
 
  
 params,prestr = params_filter(params) 
  
 params['sign'] = build_mysign(prestr, settings.ALIPAY_KEY, settings.ALIPAY_SIGN_TYPE) 
 params['sign_type'] = settings.ALIPAY_SIGN_TYPE 
  
 return _GATEWAY + urlencode(params) 
 
def notify_verify(post): 
 # 初级验证--签名 
 _,prestr = params_filter(post) 
 mysign = build_mysign(prestr, settings.ALIPAY_KEY, settings.ALIPAY_SIGN_TYPE) 
 
 if mysign != post.get('sign'): 
  return False 
  
 # 二级验证--查询支付宝服务器此条信息是否有效 
 params = {} 
 params['partner'] = settings.ALIPAY_PARTNER 
 params['notify_id'] = post.get('notify_id') 
 
 gateway = 'https://mapi.alipay.com/gateway.do?service=notify_verify&' 
 verify_result = urlopen(gateway, urlencode(params)).read() 
 if verify_result.lower().strip() == 'true': 
  return True 
 return False 

""" 
The md5 and sha modules are deprecated since Python 2.5, replaced by the 
hashlib module containing both hash algorithms. Here, we provide a common 
interface to the md5 and sha constructors, preferring the hashlib module when 
available. 
""" 
 
try: 
 import hashlib 
 md5_constructor = hashlib.md5 
 md5_hmac = md5_constructor 
 sha_constructor = hashlib.sha1 
 sha_hmac = sha_constructor 
except ImportError: 
 import md5 
 md5_constructor = md5.new 
 md5_hmac = md5 
 import sha 
 sha_constructor = sha.new 
 sha_hmac = sha 

#-*- coding:utf-8 -*- 
 
class settings: 
 # 安全检验码，以数字和字母组成的32位字符 
 ALIPAY_KEY = 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx' 
 
 ALIPAY_INPUT_CHARSET = 'utf-8' 
 
 # 合作身份者ID，以2088开头的16位纯数字 
 ALIPAY_PARTNER = 'xxxxxxxxxxxxxxxx' 
 
 # 签约支付宝账号或卖家支付宝帐户 
 ALIPAY_SELLER_EMAIL = 'ls@abc.com' 
 
 ALIPAY_SIGN_TYPE = 'MD5' 
 
 # 付完款后跳转的页面（同步通知） 要用 http://格式的完整路径，不允许加?id=123这类自定义参数 
 ALIPAY_RETURN_URL='http://www.xxx.com/alipay/return/' 
 
 # 交易过程中服务器异步通知的页面 要用 http://格式的完整路径，不允许加?id=123这类自定义参数 
 ALIPAY_NOTIFY_URL='http://www.xxx.com/alipay/notify/' 

#确认支付 
def pay(request): 
 cbid=request.POST.get('id') 
 try: 
  cb=cBill.objects.get(id=cbid) 
 except ObjectDoesNotExist: 
  return HttpResponseRedirect("/err/no_object") 
  
 #如果网关是支付宝 
 if cb.cbank.gateway=='alipay': 
   tn=cb.id 
   subject='' 
   body='' 
   bank=cb.cbank.id 
   tf='%.2f' % cb.amount 
   url=create_direct_pay_by_user (tn,subject,body,bank,tf) 
 
 #如果网关是财付通 
 elif cb.cbank.gateway=='tenpay': 
  pass 
  
 #去支付页面 
 return HttpResponseRedirect (url) 
 
#alipay异步通知 
 
@csrf_exempt 
def alipay_notify_url (request): 
 if request.method == 'POST': 
  if notify_verify (request.POST): 
   #商户网站订单号 
   tn = request.POST.get('out_trade_no') 
   #支付宝单号 
   trade_no=request.POST.get('trade_no') 
   #返回支付状态 
   trade_status = request.POST.get('trade_status') 
   cb = cBill.objects.get(pk=tn) 
    
   if trade_status == 'TRADE_SUCCESS': 
    cb.exe() 
    log=Log(operation='notify1_'+trade_status+'_'+trade_no) 
    log.save() 
    return HttpResponse("success") 
   else: 
    #写入日志 
    log=Log(operation='notify2_'+trade_status+'_'+trade_no) 
    log.save() 
    return HttpResponse ("success") 
  else: 
   #黑客攻击 
   log=Log(operation='hack_notify_'+trade_status+'_'+trade_no+'_'+'out_trade_no') 
   log.save() 
 return HttpResponse ("fail") 
 
#同步通知 
 
def alipay_return_url (request): 
 if notify_verify (request.GET): 
  tn = request.GET.get('out_trade_no') 
  trade_no = request.GET.get('trade_no') 
  trade_status = request.GET.get('trade_status') 
   
  cb = cBill.objects.get(pk=tn) 
  log=Log(operation='return_'+trade_status+'_'+trade_no) 
  log.save() 
  return HttpResponseRedirect ("/public/verify/"+tn) 
 else: 
  #错误或者黑客攻击 
  log=Log(operation='err_return_'+trade_status+'_'+trade_no) 
  log.save() 
  return HttpResponseRedirect ("/") 
 
 
#外部跳转回来的链接session可能丢失，无法再进入系统。 
#客户可能通过xxx.com操作，但是支付宝只能返回www.xxx.com，域名不同，session丢失。 
def verify(request,cbid): 
 try: 
  cb=cBill.objects.get(id=cbid) 
  #如果订单时间距现在超过1天，跳转到错误页面！ 
  #避免网站信息流失 
   
  return render_to_response('public_verify.html',{'cb':cb},RequestContext(request)) 
 except ObjectDoesNotExist: 
  return HttpResponseRedirect("/err/no_object")