arguments,configuration: fstring in use

freqtrade/arguments.py

@@ -72,7 +72,7 @@ class Arguments(object):
         self.parser.add_argument(
             '--version',
             action='version',
-            version='%(prog)s {}'.format(__version__),
+            version=f'%(prog)s {__version__}'
         )
         self.parser.add_argument(
             '-c', '--config',

freqtrade/configuration.py

@@ -236,9 +236,8 @@ class Configuration(object):
         exchange = config.get('exchange', {}).get('name').lower()
         if exchange not in ccxt.exchanges:
 
-            exception_msg = 'Exchange "{}" not supported.\n' \
-                            'The following exchanges are supported: {}'\
-                .format(exchange, ', '.join(ccxt.exchanges))
+            exception_msg = f'Exchange "{exchange}" not supported.\n' \
+                            f'The following exchanges are supported: {", ".join(ccxt.exchanges)}'
 
             logger.critical(exception_msg)
             raise OperationalException(