token验证函数， 如果提示验证失败请检查1.你的url是否正确，2. 验证函数代码是否正确， 3.端口是否是80端口的， 4.返回值是否是echoster(4容易忽略)

def wxcsh_signature(form):

print form

signature = form['signature']

timestamp = form['timestamp']

nonce = form['nonce']

echostr = form['echostr']

print TOKEN, echostr

lists = [TOKEN, timestamp, nonce]

lists.sort()

hashcode = sha1(''.join(lists)).hexdigest()

if hashcode == signature:

print hashcode, signature

return echostr

return ''