Get trade fee.

        https://github.com/binance-exchange/binance-official-api-docs/blob/master/wapi-api.md#trade-fee-user_data

        :param symbol: optional
        :type symbol: str
        :param recvWindow: the number of milliseconds the request is valid for
        :type recvWindow: int

        :returns: API response

        .. code-block:: python

            {
                "tradeFee": [
                    {
                        "symbol": "ADABNB",
                        "maker": 0.9000,
                        "taker": 1.0000
                    }, {
                        "symbol": "BNBBTC",
                        "maker": 0.3000,
                        "taker": 0.3000
                    }
                ],
                "success": true
            }

        :raises: BinanceWithdrawException

def get_trade_fee(self, **params):
        """Get trade fee.

        https://github.com/binance-exchange/binance-official-api-docs/blob/master/wapi-api.md#trade-fee-user_data

        :param symbol: optional
        :type symbol: str
        :param recvWindow: the number of milliseconds the request is valid for
        :type recvWindow: int

        :returns: API response

        .. code-block:: python

            {
                "tradeFee": [
                    {
                        "symbol": "ADABNB",
                        "maker": 0.9000,
                        "taker": 1.0000
                    }, {
                        "symbol": "BNBBTC",
                        "maker": 0.3000,
                        "taker": 0.3000
                    }
                ],
                "success": true
            }

        :raises: BinanceWithdrawException

        """
        res = self._request_withdraw_api('get', 'tradeFee.html', True, data=params)
        if not res['success']:
            raise BinanceWithdrawException(res['msg'])
        return res