code: def api_key_post(params, request_path, _async=False):
      
      method = 'POST'
      timestamp = datetime.datetime.utcnow().strftime('%Y-%m-%dT%H:%M:%S')
      params_to_sign = {
          'AccessKeyId': ACCESS_KEY,
          'SignatureMethod': 'HmacSHA256',
          'SignatureVersion': '2',
          'Timestamp': timestamp
      }
  
      host_url = TRADE_URL
      host_name = urllib.parse.urlparse(host_url).hostname
      host_name = host_name.lower()
      secret_sign = createSign(params_to_sign, method, host_name,
                                               request_path, SECRET_KEY)
      params_to_sign['Signature'] = secret_sign
      if PRIVATE_KEY:
          params_to_sign['PrivateSignature'] = createPrivateSign(secret_sign, PRIVATE_KEY)
      url = host_url + request_path + '?' + urllib.parse.urlencode(params_to_sign)
      return http_post_request(url, params, _async=_async)
docs: from 火币demo, 构造post请求并调用post方法
      :param params:
      :param request_path:
      :return: