When I substract two datetime object in python it is considering only time not taking day

Question

I have two date time objects

`statrt_time` and `end_time`

my code is

if self.book_from and  self.book_to:
        fmt = '%Y-%m-%d %H:%M:%S'
        s = datetime.strptime(self.book_from,fmt)   #start date
        e = datetime.strptime(self.book_to,fmt)   #end date
        diff = e - s

        total_seconds=diff.seconds
        time_diff = (total_seconds/3600.0)
        no_of_units = (time_diff/4)
        if(e<s):
            self.units = 0
        else:
            self.units = math.ceil(no_of_units)

Here when I subtract time within the same day it is giving the correct difference. But when the day is changed, it is not calculating the day difference but only giving time difference. How can I add day difference also?

Answer 1

Use total_seconds() instead of seconds.

timedelta.seconds just shows "second" part of the difference, while total_seconds() shows the duration of the difference in seconds. See Mureinik's answer for more details.

So, use this:

total_seconds=diff.total_seconds()

Answer 2

total_seconds is a timedelta object which stores the difference between two datetimes using three fields - days, seconds and miliseconds. Your snippet just uses the seconds attributes instead of the entire difference. The total_seconds() method takes care of this for you and returns, well, the total number of seconds between two datatimes.