def send_order(self, acc_id, amount, symbol, _type, price=0, site='Pro', _async=False):
        """
        创建并执行订单
        :param amount:
        :param source: 如果使用借贷资产交易，请在下单接口,请求参数source中填写'margin-api'
        :param symbol:
        :param _type: 可选值 {buy-market：市价买, sell-market：市价卖, buy-limit：限价买, sell-limit：限价卖, buy-ioc：IOC买单, sell-ioc：IOC卖单}
        :param price:
        :return:
        """
        assert site in ['Pro', 'HADAX']
        assert _type in u.ORDER_TYPE
        params = {
            'account-id': acc_id,
            'amount': amount,
            'symbol': symbol,
            'type': _type,
            'source': 'api'
        }
        if price:
            params['price'] = price

        path = f'/v1{"/" if site == "Pro" else "/hadax/"}order/orders/place'
        return api_key_post(params, path, _async=_async)
创建并执行订单
        :param amount:
        :param source: 如果使用借贷资产交易，请在下单接口,请求参数source中填写'margin-api'
        :param symbol:
        :param _type: 可选值 {buy-market：市价买, sell-market：市价卖, buy-limit：限价买, sell-limit：限价卖, buy-ioc：IOC买单, sell-ioc：IOC卖单}
        :param price:
        :return: