Add mode argument, default 'total'

time.txt in the current directory is the default, but another path can be passed too.

time.txt

@@ -0,0 +1,4 @@
+2020-08-12 01:00 Work on Task 1
+2020-08-12 03:00 Work on Task 2
+2020-08-16 05:00 Finish Task 2
+2020-08-31 -08:00 Fee note for August

tx

@@ -0,0 +1,34 @@
+#!/usr/bin/env python3
+
+from datetime import datetime, timedelta
+import argparse
+
+# Parse command line arguments
+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()
+
+if args.file:
+    time_file = open(args.file,'r')
+else:
+    time_file = open('time.txt','r')
+
+if args.mode == "total":
+    total_time = timedelta()
+
+    for line in time_file:
+        date_time_description = line.split(" ", 2)
+        
+        hours, minutes = date_time_description[1].split(':', 1)
+        delta = timedelta(hours=int(hours), minutes=int(minutes))
+        
+        total_time += delta
+
+    print('Total time: ', total_time)