When parameter names are meaningless for the final result def abs_days_difference(date1, date2, /): # note that swapping passed params will yield the sam

When parameter names are meaningless for the final result def abs_days_difference(date1, date2, /): # note that swapping passed params will yield the same result delta = abs((date2 - date1).days) return delta d1 = date(2023, 1, 1) d2 = date(2024, 1, 15) abs_days_difference(d1,d2)==abs_days_difference(d2,d1) The function returns the absolute diff in the number of days, so date1, date2 are meaningless variable names. It looks like then introduce an order(could #1 be the earlier date, while #2 be the later one?). If you don't get users any options it is clear that the order is meaningless Compare with def day_difference(earlier_date, later_date): delta = (later_date - earlier_date).days return delta Note that now d1 = date(2023, 1, 1) d2 = date(2024, 1, 15) day_difference(d1,d2)!=day_difference(d2,d1) If you function signature is day_difference(date1, date2,*) you have to specify params as kwargs only, removing the confusion: d1 = date(2023, 1, 1) d2 = date(2024, 1, 15) #this now doesn't work day_difference(d1,d2) # this works and is much clearer for caller day_difference(earlier_date=d1,later_date=d2)