Django实现支付宝付款和微信支付的示例代码

from django.db import models
from django.contrib.postgres.fields import arrayfield

# create your models here.
class basemodel(models.model):
 """
  基础模型
 """
 created_time = models.datetimefield(auto_now_add=true, verbose_name="创建时间")
 updated_time = models.datetimefield(auto_now=true, verbose_name="修改时间")
 created_by = models.integerfield(verbose_name="创建人id")
 updated_by = models.integerfield(verbose_name="修改人id")
 is_active = models.booleanfield(default=true, verbose_name='是否正常')

 class meta:
  abstract = true


class alipay(basemodel):
 """
  支付
 """

 subject = models.charfield(max_length=256, verbose_name="订单标题")
 out_trade_no = models.charfield(max_length=64, unique=true, verbose_name="唯一订单号")
 trade_no = models.charfield(default="", max_length=64, verbose_name="支付宝系统中的交易流水号")
 total_amount = models.decimalfield(max_digits=11, decimal_places=2, verbose_name="订单的资金总额")
 return_url = models.charfield(max_length=500, verbose_name="支付完成同步跳转地址")
 notify_url = models.charfield(max_length=500, verbose_name="支付完成异步通知rpc地址")
 pay_time = models.datetimefield(null=true, blank=true, verbose_name="支付时间")
 pay_nos = arrayfield(models.charfield(max_length=100), default=[], verbose_name='同一订单的支付id数组')

 class meta:
  verbose_name = "阿里支付"
  verbose_name_plural = verbose_name
  ordering = ('-created_time',)


class wxorder(basemodel):
 """
  订单
 """
 body = models.charfield(max_length=256, verbose_name="商品描述")
 out_trade_no = models.charfield(max_length=64, unique=true, verbose_name="订单号")
 transaction_id = models.charfield(default="", max_length=64, verbose_name="微信支付订单号")
 total_fee = models.bigintegerfield(verbose_name="订单的资金总额,单位为分")
 product_id = models.charfield(max_length=16, verbose_name="商品id")
 notify_url = models.charfield(max_length=500, verbose_name="支付完成通知url")
 pay_time = models.datetimefield(null=true, blank=true, verbose_name="支付时间")

 class meta:
  verbose_name = "微信订单"
  verbose_name_plural = verbose_name
  ordering = ('-created_time',)


class wxpay(basemodel):
 """
  微信支付
 """
 out_trade_no = models.charfield(null=true, blank=true, max_length=64, verbose_name="订单号")
 pay_no = models.charfield(null=true, blank=true, max_length=64, unique=true, verbose_name="支付唯一订单号")
 code_url = models.charfield(null=true, blank=true, max_length=100, verbose_name="二维码地址")
 nonce_str = models.charfield(null=true, blank=true, max_length=32, verbose_name="随机字符串")

 class meta:
  verbose_name = "微信支付"
  verbose_name_plural = verbose_name
  ordering = ('-created_time',)

from django.conf import settings
from rest_framework import serializers
from pay.models import alipay, wxpay

class baseserializer(serializers.modelserializer):
 created_time = serializers.datetimefield(format=settings.datetime_format, read_only=true)
 updated_time = serializers.datetimefield(format=settings.datetime_format, read_only=true)
 is_active = serializers.booleanfield(read_only=true)

 class meta:
  model = none


class alipayserializer(baseserializer):
 """
  阿里支付序列化类
 """

 class meta:
  model = alipay
  fields = "__all__"


class wxpayserializer(baseserializer):
 """
  阿里支付序列化类
 """

 class meta:
  model = wxpay
  fields = "__all__"

# -*- coding=utf-8 -*-
# create your views here.
import time
import dicttoxml
from jsonrpc import jsonrpc_method
from rest_framework.decorators import list_route
from rest_framework.response import response
from rest_framework.viewsets import modelviewset
from rest_framework.views import apiview
from rest_framework_xml.parsers import xmlparser
from rest_framework_xml.renderers import xmlrenderer
from tokenauth.decorators import is_login
from pay import utils
from pay.weixin_pay import weixinpay, unifiedorderpay, orderquery
from pay.uuidtools import uuidtools
from pay.models import alipay, wxpay, wxorder
from pay.serializers import alipayserializer, wxpayserializer
from pay.utils import unactivemodelmixin
from pay.alipay import alipay
from pay_service.settings.base import appid, private_key_path, \
 ali_pub_key_path, alipay_callback_url, \
 wxappid, wx_pay_key, wx_mch_id, wxpay_callback_url

notify_url = alipay_callback_url + 'api/v1.0/pay/alipay/notify/'

class alipayviewset(modelviewset):
 queryset = alipay.objects.filter(is_active=true)
 serializer_class = alipayserializer

 @list_route(methods=['post'])
 def notify(self, request):
  """ 
   处理支付宝的notify_url
  :param request:
  :return:
  """
  processed_dict = {}
  for k, v in request.data.items():
   processed_dict[k] = v
  app_id = processed_dict.get('app_id')
  pay_no = processed_dict.get('out_trade_no')
  trade_no = processed_dict.get('trade_no')
  total_amount = processed_dict.get('total_amount')
  pay_time = time.strftime('%y-%m-%d %h:%m:%s',time.localtime())

  alipay = alipay.objects.filter(pay_nos__contains=[pay_no]).values().first()
  if alipay is none:
   return response("failed")
  if str(alipay.get('total_amount')) != str(total_amount):
   return response("failed")
  if app_id != appid:
   return response("failed")
  if alipay.get('trade_no') != "":
   return response("failed")

  sign = processed_dict.pop('sign', none)

  ali_pay = alipay(
   appid=appid,
   app_notify_url=notify_url,
   app_private_key_path=private_key_path,
   alipay_public_key_path=ali_pub_key_path,
   debug=true, # 默认false,
   return_url=alipay.get('return_url')
  )

  is_verify = ali_pay.verify(processed_dict, sign)

  if is_verify is true:
   alipay.objects.filter(pk=alipay.get('id')).update(pay_time=pay_time, trade_no=trade_no)
   ret = utils.request_thrift('tradingmanager', 'notify',
    settings.trading_rpc_ip, int(settings.trading_rpc_port),
    alipay.get('out_trade_no'), str(pay_time))
   if ret == "success":
    return response("success")


class wxpayviewset(modelviewset):
 queryset = wxpay.objects.filter(is_active=true)
 serializer_class = wxpayserializer
 parser_classes = (xmlparser,)
 renderer_classes = (xmlrenderer,)


@jsonrpc_method('pay.get_alipay_url')
def get_alipay_url(request, subject, out_trade_no, total_amount, return_url, notify_url, user_id):
 recode = alipay.objects.filter(out_trade_no=out_trade_no).values().first()
 if recode is not none:
  pay_no = uuidtools.datetime_random()
  alipay = alipay.objects.get(pk=recode.get('id'))
  alipay.pay_nos.append(pay_no)
  alipay.save()
 else:
  pay_no = out_trade_no
  alipay.objects.create(subject=subject,
        out_trade_no=out_trade_no,
        total_amount=total_amount,
        return_url=return_url,
        notify_url=notify_url,
        pay_nos=[pay_no],
        created_by=user_id,
        updated_by=user_id
        )

 ali_pay = alipay(
  appid=appid,
  app_notify_url=notify_url,
  app_private_key_path=private_key_path,
  alipay_public_key_path=ali_pub_key_path,
  debug=true, # 默认false,
  return_url=return_url
 )

 total_amount = "%.2f" % float(total_amount)
 url = ali_pay.direct_pay(
  subject=subject,
  out_trade_no=pay_no,
  total_amount=total_amount
 )
 # 沙箱环境网关
 # alipay_url = "https://openapi.alipaydev.com/gateway.do?{data}".format(data=url)
 # 正式环境网关
 alipay_url = "https://openapi.alipay.com/gateway.do?{data}".format(data=url)
 return alipay_url


@jsonrpc_method('pay.get_wxpay_url')
def get_wxpay_url(request, out_trade_no, body, total_fee, notify_url, product_id, user_id):
 recode = wxorder.objects.filter(out_trade_no=out_trade_no).values().first()
 if recode is none:
  wxorder.objects.create(
   out_trade_no=out_trade_no,
   body=body,
   total_fee=total_fee,
   notify_url=notify_url,
   product_id=product_id,
   created_by=user_id,
   updated_by=user_id
  )

 pay_no = uuidtools.datetime_random()
 pay = unifiedorderpay(wxappid, wx_mch_id, wx_pay_key)
 response = pay.post(body, pay_no, total_fee,
      wxpay_callback_url.split('://')[1].split(':')[0], wx_notify_url)
 if response and response["return_code"] == "success" and response["result_code"] == "success":
  wxorder = wxorder.objects.filter(out_trade_no=out_trade_no).values().first()
  wxpay.objects.create(
   out_trade_no=out_trade_no,
   pay_no=pay_no,
   code_url=response.get('code_url'),
   nonce_str=response.get('nonce_str'),
   created_by=user_id,
   updated_by=user_id
  )
  return response.get('code_url')


@jsonrpc_method('pay.wx_order_query')
def wx_order_query(request, out_trade_no):
 wxpays = wxpay.objects.filter(out_trade_no=out_trade_no).values()
 pay = orderquery(wxappid, wx_mch_id, wx_pay_key)
 for wxpay in wxpays:
  response = pay.post(wxpay.get('pay_no'))
  if response and response["return_code"] == "success" \
    and response["result_code"] == "success":
   trade_state = response["trade_state"]
   if trade_state == "success": # 支付成功
    pay_time = response["time_end"]
    transaction_id = response["transaction_id"]
    wxorder.objects.filter(out_trade_no=out_trade_no).update(
     pay_time=time.strftime("%y-%m-%d %h:%m:%s",
           time.strptime(pay_time, "%y%m%d%h%m%s")),
     transaction_id=transaction_id
    )
    return {"success": true, "pay_time": pay_time}
 return {"success": false}

# -*- coding: utf-8 -*-
# pip install pycryptodome

from datetime import datetime
from crypto.publickey import rsa
from crypto.signature import pkcs1_v1_5
from crypto.hash import sha256
from base64 import b64encode, b64decode
from urllib.parse import quote_plus
from urllib.parse import urlparse, parse_qs
from urllib.request import urlopen
from base64 import decodebytes, encodebytes

import json


class alipay(object):
 """
 支付宝支付接口
 """

 def __init__(self, appid, app_notify_url, app_private_key_path,
     alipay_public_key_path, return_url, debug=false):
  self.appid = appid
  self.app_notify_url = app_notify_url
  self.app_private_key_path = app_private_key_path
  self.app_private_key = none
  self.return_url = return_url
  with open(self.app_private_key_path) as fp:
   self.app_private_key = rsa.importkey(fp.read())

  self.alipay_public_key_path = alipay_public_key_path
  with open(self.alipay_public_key_path) as fp:
   self.alipay_public_key = rsa.import_key(fp.read())

  if debug is true:
   self.__gateway = "https://openapi.alipaydev.com/gateway.do"
  else:
   self.__gateway = "https://openapi.alipay.com/gateway.do"

 def direct_pay(self, subject, out_trade_no, total_amount, return_url=none, **kwargs):
  biz_content = {
   "subject": subject,
   "out_trade_no": out_trade_no,
   "total_amount": total_amount,
   "product_code": "fast_instant_trade_pay",
   # "qr_pay_mode":4
  }

  biz_content.update(kwargs)
  data = self.build_body("alipay.trade.page.pay", biz_content, self.return_url)
  return self.sign_data(data)

 def build_body(self, method, biz_content, return_url=none):
  data = {
   "app_id": self.appid,
   "method": method,
   "charset": "utf-8",
   "sign_type": "rsa2",
   "timestamp": datetime.now().strftime("%y-%m-%d %h:%m:%s"),
   "version": "1.0",
   "biz_content": biz_content
  }

  if return_url is not none:
   data["notify_url"] = self.app_notify_url
   data["return_url"] = self.return_url

  return data

 def sign_data(self, data):
  data.pop("sign", none)
  # 排序后的字符串
  unsigned_items = self.ordered_data(data)
  unsigned_string = "&".join("{0}={1}".format(k, v) for k, v in unsigned_items)
  sign = self.sign(unsigned_string.encode("utf-8"))
  ordered_items = self.ordered_data(data)
  quoted_string = "&".join("{0}={1}".format(k, quote_plus(v)) for k, v in ordered_items)

  # 获得最终的订单信息字符串
  signed_string = quoted_string + "&sign=" + quote_plus(sign)
  return signed_string

 def ordered_data(self, data):
  complex_keys = []
  for key, value in data.items():
   if isinstance(value, dict):
    complex_keys.append(key)

  # 将字典类型的数据dump出来
  for key in complex_keys:
   data[key] = json.dumps(data[key], separators=(',', ':'))

  return sorted([(k, v) for k, v in data.items()])

 def sign(self, unsigned_string):
  # 开始计算签名
  key = self.app_private_key
  signer = pkcs1_v1_5.new(key)
  signature = signer.sign(sha256.new(unsigned_string))
  # base64 编码，转换为unicode表示并移除回车
  sign = encodebytes(signature).decode("utf8").replace("\n", "")
  return sign

 def _verify(self, raw_content, signature):
  # 开始计算签名
  key = self.alipay_public_key
  signer = pkcs1_v1_5.new(key)
  digest = sha256.new()
  digest.update(raw_content.encode("utf8"))
  if signer.verify(digest, decodebytes(signature.encode("utf8"))):
   return true
  return false

 def verify(self, data, signature):
  if "sign_type" in data:
   sign_type = data.pop("sign_type")
  # 排序后的字符串
  unsigned_items = self.ordered_data(data)
  message = "&".join(u"{}={}".format(k, v) for k, v in unsigned_items)
  return self._verify(message, signature)


if __name__ == "__main__":
 alipay = alipay(
  appid="2016081500252338",
  app_notify_url="http://projectsedus.com/",
  app_private_key_path="keys/private_2048.txt",
  alipay_public_key_path="keys/alipay_key_2048.txt", # 支付宝的公钥，验证支付宝回传消息使用，不是你自己的公钥,
  debug=true, # 默认false,
  return_url="http://192.168.247.129:8000/"
 )

 url = alipay.direct_pay(
  subject="测试订单",
  out_trade_no="20170202126666",
  total_amount=1000
 )
 re_url = "https://openapi.alipaydev.com/gateway.do?{data}".format(data=url)
 print(re_url)

# -*- coding=utf-8 -*-

import time
import json
import hashlib
import requests

from pay.utils import (smart_str, dict_to_xml, calculate_sign, random_str,
      post_xml, xml_to_dict, validate_post_xml, format_url)

# from local_settings import appid, mch_id, api_key


oauth2_authorize_url = "https://open.weixin.qq.com/connect/oauth2/authorize?%s"
oauth2_access_token_url = "https://api.weixin.qq.com/sns/oauth2/access_token?%s"


class weixinpay(object):
 def __init__(self, appid, mch_id, api_key):
  self.appid = appid # 微信公众号身份的唯一标识。审核通过后，在微信发送的邮件中查看
  self.mch_id = mch_id # 受理商id，身份标识
  self.api_key = api_key # 商户支付密钥key。审核通过后，在微信发送的邮件中查看
  self.common_params = {
   "appid": self.appid,
   "mch_id": self.mch_id,
  }
  self.params = {}
  self.url = ""
  self.trade_type = ""

 def set_params(self, **kwargs):
  self.params = {}
  for (k, v) in kwargs.items():
   self.params[k] = smart_str(v)

  self.params["nonce_str"] = random_str(32)
  if self.trade_type:
   self.params["trade_type"] = self.trade_type
  self.params.update(self.common_params)

 def post_xml(self):
  sign = calculate_sign(self.params, self.api_key)
  xml = dict_to_xml(self.params, sign)
  response = post_xml(self.url, xml)
  return xml_to_dict(response.text)

 def valiate_xml(self, xml):
  return validate_post_xml(xml, self.appid, self.mch_id, self.api_key)

 def get_error_code_desc(self, error_code):
  error_desc = {
   "systemerror": u"接口后台错误",
   "invalid_transactionid": u"无效 transaction_id",
   "param_error": u"提交参数错误",
   "orderpaid": u"订单已支付",
   "out_trade_no_used": u"商户订单号重复",
   "noauth": u"商户无权限",
   "notenough": u"余额丌足",
   "notsuportcard": u"不支持卡类型",
   "orderclosed": u"订单已关闭",
   "bankerror": u"银行系统异常",
   "refund_fee_invalid": u"退款金额大亍支付金额",
   "ordernotexist": u"订单不存在",
  }
  return error_desc.get(error_code.strip().upper(), u"未知错误")


class unifiedorderpay(weixinpay):
 """发送预支付单"""

 def __init__(self, appid, mch_id, api_key):
  super(unifiedorderpay, self).__init__(appid, mch_id, api_key)
  self.url = "https://api.mch.weixin.qq.com/pay/unifiedorder"
  self.trade_type = "native"

 def post(self, body, out_trade_no, total_fee, spbill_create_ip, notify_url, **kwargs):
  tmp_kwargs = {
   "body": body,
   "out_trade_no": out_trade_no,
   "total_fee": total_fee,
   "spbill_create_ip": spbill_create_ip,
   "notify_url": notify_url,
  }
  tmp_kwargs.update(**kwargs)
  self.set_params(**tmp_kwargs)
  return self.post_xml()[1]


class orderquery(weixinpay):
 """订单状态查询"""

 def __init__(self, appid, mch_id, api_key):
  super(orderquery, self).__init__(appid, mch_id, api_key)
  self.url = "https://api.mch.weixin.qq.com/pay/orderquery"

 def post(self, out_trade_no):
  self.set_params(out_trade_no=out_trade_no)
  return self.post_xml()[1]


class jsapiorderpay(unifiedorderpay):
 """h5页面的js调用类"""

 def __init__(self, appid, mch_id, api_key, app_secret):
  super(jsapiorderpay, self).__init__(appid, mch_id, api_key)
  self.app_secret = app_secret
  self.trade_type = "jsapi"

 def create_oauth_url_for_code(self, redirect_uri):
  url_params = {
   "appid": self.appid,
   "redirect_uri": redirect_uri, # 一般是回调当前页面
   "response_type": "code",
   "scope": "snsapi_base",
   "state": "state#wechat_redirect"
  }
  url = format_url(url_params)
  return oauth2_authorize_url % url

 def _create_oauth_url_for_openid(self, code):
  url_params = {
   "appid": self.appid,
   "secret": self.app_secret,
   "code": code,
   "grant_type": "authorization_code",
  }
  url = format_url(url_params)
  return oauth2_access_token_url % url

 def _get_oauth_info(self, code):
  """
  获取oauth2的信息：access_token、expires_in、refresh_token、openid、scope
  返回结果为字典，可使用["xxx"]或.get("xxx", none)的方式进行读取
  """
  url = self._create_oauth_url_for_openid(code)
  response = requests.get(url)
  return response.json() if response else none

 def _get_openid(self, code):
  oauth_info = self._get_oauth_info(code)
  if oauth_info:
   return oauth_info.get("openid", none)
  return none

 def _get_json_js_api_params(self, prepay_id):
  js_params = {
   "appid": self.appid,
   "timestamp": "%d" % time.time(),
   "noncestr": random_str(32),
   "package": "prepay_id=%s" % prepay_id,
   "signtype": "md5",
  }
  js_params["paysign"] = calculate_sign(js_params, self.api_key)
  return js_params

 def post(self, body, out_trade_no, total_fee, spbill_create_ip, notify_url, code):
  if code:
   open_id = self._get_openid(code)
   if open_id:
    # 直接调用基类的post方法查询prepay_id，如果成功，返回一个字典
    unified_order = super(jsapiorderpay, self).post(body, out_trade_no, total_fee, spbill_create_ip,
                notify_url, open_id=open_id)
    if unified_order:
     prepay_id = unified_order.get("prepay_id", none)
     if prepay_id:
      return self._get_json_js_api_params(prepay_id)
  return none

# -*- coding=utf-8 -*-
import hashlib
import re
import types
from random import random
import requests
import thriftpy

from django.conf import settings
from django.core.exceptions import fielddoesnotexist
from django.db import models
from django.db.models.fields.reverse_related import foreignobjectrel
from rest_framework.pagination import pagenumberpagination
from thriftpy.rpc import make_client

from pay.exception_handler import foreignobjectreldeleteerror, modeldonthaveisactivefiled, logger


def smart_str(s, encoding='utf-8', strings_only=false, errors='strict'):
 """
 returns a bytestring version of 's', encoded as specified in 'encoding'.
 if strings_only is true, don't convert (some) non-string-like objects.
 """
 if strings_only and isinstance(s, (types.nonetype, int)):
  return s
 if not isinstance(s, str):
  try:
   return str(s)
  except unicodeencodeerror:
   if isinstance(s, exception):
    # an exception subclass containing non-ascii data that doesn't
    # know how to print itself properly. we shouldn't raise a
    # further exception.
    return ' '.join([smart_str(arg, encoding, strings_only,
           errors) for arg in s])
   return unicode(s).encode(encoding, errors)
 elif s and encoding != 'utf-8':
  return s.decode('utf-8', errors).encode(encoding, errors)
 else:
  return s


def format_url(params, api_key=none):
 url = "&".join(['%s=%s' % (key, smart_str(params[key])) for key in sorted(params)])
 if api_key:
  url = '%s&key=%s' % (url, api_key)
 return url


def calculate_sign(params, api_key):
 # 签名步骤一：按字典序排序参数, 在string后加入key
 url = format_url(params, api_key)
 # 签名步骤二：md5加密, 所有字符转为大写
 return hashlib.md5(url.encode('utf-8')).hexdigest().upper()


def dict_to_xml(params, sign):
 xml = ["<xml>", ]
 for (k, v) in params.items():
  if (v.isdigit()):
   xml.append('<%s>%s</%s>' % (k, v, k))
  else:
   xml.append('<%s><![cdata[%s]]></%s>' % (k, v, k))
 xml.append('<sign><![cdata[%s]]></sign></xml>' % sign)
 return ''.join(xml)


def xml_to_dict(xml):
 if xml[0:5].upper() != "<xml>" and xml[-6].upper() != "</xml>":
  return none, none

 result = {}
 sign = none
 content = ''.join(xml[5:-6].strip().split('\n'))

 pattern = re.compile(r"<(?p<key>.+)>(?p<value>.+)</(?p=key)>")
 m = pattern.match(content)
 while (m):
  key = m.group("key").strip()
  value = m.group("value").strip()
  if value != "<![cdata[]]>":
   pattern_inner = re.compile(r"<!\[cdata\[(?p<inner_val>.+)\]\]>")
   inner_m = pattern_inner.match(value)
   if inner_m:
    value = inner_m.group("inner_val").strip()
   if key == "sign":
    sign = value
   else:
    result[key] = value

  next_index = m.end("value") + len(key) + 3
  if next_index >= len(content):
   break
  content = content[next_index:]
  m = pattern.match(content)

 return sign, result


def validate_post_xml(xml, appid, mch_id, api_key):
 sign, params = xml_to_dict(xml)
 if (not sign) or (not params):
  return none

 remote_sign = calculate_sign(params, api_key)
 if sign != remote_sign:
  return none

 if params["appid"] != appid or params["mch_id"] != mch_id:
  return none

 return params


def random_str(randomlength=8):
 chars = 'abcdefghijklmnopqrstuvwxyz0123456789'
 random = random()
 return "".join([chars[random.randint(0, len(chars) - 1)] for i in range(randomlength)])


def post_xml(url, xml):
 return requests.post(url, data=xml.encode('utf-8'), verify=false)


class unactivemodelmixin(object):
 """
 删除一个对象，并不真删除，级联将对应外键对象的is_active设置为false，需要外键对象都有is_active字段.
 """

 def perform_destroy(self, instance):
  rel_fileds = [f for f in instance._meta.get_fields() if isinstance(f, foreignobjectrel)]

  links = [f.get_accessor_name() for f in rel_fileds]

  for link in links:
   manager = getattr(instance, link, none)
   if not manager:
    continue
   if isinstance(manager, models.model):
    if hasattr(manager, 'is_active') and manager.is_active:
     manager.is_active = false
     manager.save()
     raise foreignobjectreldeleteerror(u'{} 上有关联数据'.format(link))
   else:
    if not manager.count():
     continue
    try:
     manager.model._meta.get_field('is_active')
     manager.filter(is_active=true).update(is_active=false)
    except fielddoesnotexist as ex:
     # 理论上，级联删除的model上面应该也有is_active字段，否则代码逻辑应该有问题
     logger.warn(ex)
     raise modeldonthaveisactivefiled(
      '{}.{} 没有is_active字段, 请检查程序逻辑'.format(
       manager.model.__module__,
       manager.model.__class__.__name__
      ))
  instance.is_active = false
  instance.save()

 def get_queryset(self):
  return self.queryset.filter(is_active=true)


class standardresultssetpagination(pagenumberpagination):
 page_size_query_param = 'size'