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 days of the overlap. Of course I can pre-fill two sets with all dates within both ranges and the perform a set intersection but this is possibly inefficient…is there a better way apart from another solution using a long
elif section covering all cases?
- Determine the latest of the two start dates and the earliest of the two end dates.
- Compute the timedelta by subtracting them.
- If the delta is positive, that is the number of days of overlap.
Here is an example calculation:
>>> from datetime import datetime >>> from collections import namedtuple >>> Range = namedtuple('Range', ['start', 'end']) >>> r1 = Range(start=datetime(2012, 1, 15), end=datetime(2012, 5, 10)) >>> r2 = Range(start=datetime(2012, 3, 20), end=datetime(2012, 9, 15)) >>> latest_start = max(r1.start, r2.start) >>> earliest_end = min(r1.end, r2.end) >>> delta = (earliest_end - latest_start).days + 1 >>> overlap = max(0, delta) >>> overlap 52
Answered By – Raymond Hettinger
Answer Checked By – Pedro (AngularFixing Volunteer)