fix minor errors

aircox_programs/utils.py

@@ -11,7 +11,6 @@ def to_timedelta (time):
         seconds = time.second
     )
 
-
 def seconds_to_time (seconds):
     """
     Seconds to datetime.time
@@ -20,4 +19,12 @@ def seconds_to_time (seconds):
     hours, minutes = divmod(minutes, 60)
     return datetime.time(hour = hours, minute = minutes, second = seconds)
 
+def time_sum (times):
+    """
+    Sum up a list of time elements
+    """
+    seconds = sum([ time.hour * 3600 + time.minute * 60 + time.second
+                    for time in times ])
+    return seconds_to_time(seconds)
+