fixed flake8 and mypy errors

freqtrade/rpc/rpc.py

@@ -245,7 +245,7 @@ class RPC:
                         fiat_profit_sum = fiat_profit if isnan(fiat_profit_sum) \
                             else fiat_profit_sum + fiat_profit
                 trades_list.append([
-                    trade.id + f' {direction_str}',
+                    str(trade.id) + f' {direction_str}',
                     trade.pair + ('*' if (trade.open_order_id is not None
                                           and trade.close_rate_requested is None) else '')
                                + ('**' if (trade.close_rate_requested is not None) else ''),

freqtrade/rpc/telegram.py

@@ -272,7 +272,7 @@ class Telegram(RPCHandler):
         else:
             msg['profit_extra'] = ''
         is_fill = msg['type'] == RPCMessageType.SELL_FILL
-        message = [
+        message = "".join([
             f"{msg['emoji']} *{msg['exchange']}:* ",
             f"{'Exited' if is_fill else 'Exiting'} {msg['pair']} (#{msg['trade_id']})\n",
             f"*{'Profit' if is_fill else 'Unrealized Profit'}:* ",
@@ -285,8 +285,7 @@ class Telegram(RPCHandler):
             msg.get('leverage', None) is not None else "",
             f"*Amount:* `{msg['amount']:.8f}`\n",
             f"*Open Rate:* `{msg['open_rate']:.8f}`\n"
-        ]
-        message = "".join(message)
+        ])
         if msg['type'] == RPCMessageType.SELL:
             message += (f"*Current Rate:* `{msg['current_rate']:.8f}`\n"
                         f"*Close Rate:* `{msg['limit']:.8f}`")