Efficient date range overlap calculation in python?

Question

I have two date ranges where each range is determined by a start and end date (obviously, datetime.date() instances). The two ranges can overlap or not. I need the number of

Answer 1

You can use the datetimerange package: https://pypi.org/project/DateTimeRange/

from datetimerange import DateTimeRange
time_range1 = DateTimeRange("2015-01-01T00:00:00+0900", "2015-01-04T00:20:00+0900") 
time_range2 = DateTimeRange("2015-01-01T00:00:10+0900", "2015-01-04T00:20:00+0900")
tem3 = time_range1.intersection(time_range2)
if tem3.NOT_A_TIME_STR == 'NaT':  # No overlap
    S_Time = 0
else: # Output the overlap seconds
    S_Time = tem3.timedelta.total_seconds()

"2015-01-01T00:00:00+0900" inside the DateTimeRange() can also be datetime format, like Timestamp('2017-08-30 20:36:25').