Add mode argument, default 'total'

tx

@@ -8,6 +8,10 @@ parser = argparse.ArgumentParser(description="Description")
  
 # add arguments to the parser
 parser.add_argument("-f", "--file")
+parser.add_argument("mode",
+                    help="display the square of a given number",
+                    nargs='?', default="total",
+                    choices=["total"])
 
 args = parser.parse_args()
 
@@ -16,6 +20,7 @@ if args.file:
 else:
     time_file = open('time.txt','r')
 
+if args.mode == "total":
     total_time = timedelta()
 
     for line in time_file: