How to calculate difference between two dates in weeks in python

Question

I\'m trying to calculate the difference between two dates in \"weeks of year\". I can get the datetime object and get the days etc but not week numbers. I can\'t, of course,

Answer 1

To determine how many weeks are spanned by two dates. eg From 3rd Oct to 13th Oct

    October 2015
Mo     5 12 19 26
Tu     6 13 20 27
We     7 14 21 28
Th  1  8 15 22 29
Fr  2  9 16 23 30
Sa  3 10 17 24 31
Su  4 11 18 25

Code:

    import math, datetime

    start_date = datetime.date(2015, 10, 3)
    start_date_monday = (start_date - datetime.timedelta(days=start_date.weekday()))
    end_date = datetime.date(2015, 10, 13)
    num_of_weeks = math.ceil((end_date - start_date_monday).days / 7.0)

Equals 3 weeks.