Week of a month pandas

Question

I\'m trying to get week on a month, some months might have four weeks some might have five. For each date i would like to know to which week does it belongs to. I\'m mostly

Answer 1

You can get it subtracting the current week and the week of the first day of the month, but extra logic is needed to handle first and last week of the year:

def get_week(s):
    prev_week = (s - pd.to_timedelta(7, unit='d')).dt.week
    return (
        s.dt.week
        .where((s.dt.month != 1) | (s.dt.week < 50), 0)
        .where((s.dt.month != 12) | (s.dt.week > 1), prev_week + 1)
    )

def get_week_of_month(s):
    first_day_of_month = s - pd.to_timedelta(s.dt.day - 1, unit='d')
    first_week_of_month = get_week(first_day_of_month)
    current_week = get_week(s)
    return  current_week - first_week_of_month