Add subparses for modes

this allows for varying additional parameters based on mode.

tx

@@ -4,20 +4,24 @@ from datetime import datetime, timedelta
 import argparse
 
 # Parse command line arguments
-parser = argparse.ArgumentParser(description="Description")
+parser = argparse.ArgumentParser(prog='time.txt', description="Description")
+subparsers = parser.add_subparsers(help='sub-command help', dest='mode')
  
-# 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", "add"])
+
+# create the parser for the "a" command
+parser_a = subparsers.add_parser('total', help='a help')
+
+# create the parser for the "b" command
+parser_b = subparsers.add_parser('add', help='b help')
+parser_b.add_argument("time")
+parser_b.add_argument("description")
 
 args = parser.parse_args()
 
 filename = args.file if args.file else 'time.txt'
 
-if args.mode == "total":
+if not args.mode or args.mode == "total":
     with open(filename, 'r') as time_file:
         total_time = timedelta()