date_range.py

# -*- coding: utf-8 -*-
#
# Author: Pavel Reznikov <pashka.reznikov@gmail.com>
# Created: 10/6/11
#
# Id: $Id$

from datetime import datetime, timedelta


class DateRange(object):
    Today = 1
    Yesterday = 2
    ThisWeekSunToday = 3
    ThisWeekMonToday = 4
    Last7Days = 5
    LastWeekSunSat = 6
    LastWeekMonSun = 7
    LastBusinessWeek = 8
    Last14Days = 9
    ThisMonth = 10
    Last30Days = 11
    LastMonth = 12
    AllTime = 13
    CustomDateRange = 14


def get_date_range(range, d1=None, d2=None, d0=None):
    """
    >>> from datetime import datetime
    >>> d = datetime(2011, 10, 6)
    >>> d.date()
    datetime.date(2011, 10, 6)

    >>> get_date_range(DateRange.Today)
    (datetime.date(2011, 10, 6), datetime.date(2011, 10, 6))

    >>> get_date_range(DateRange.Yesterday)
    (datetime.date(2011, 10, 5), datetime.date(2011, 10, 5))

    >>> get_date_range(DateRange.ThisWeekSunToday)
    (datetime.date(2011, 10, 2), datetime.date(2011, 10, 6))

    >>> get_date_range(DateRange.ThisWeekMonToday)
    (datetime.date(2011, 10, 3), datetime.date(2011, 10, 6))

    >>> get_date_range(DateRange.Last7Days)
    (datetime.date(2011, 9, 29), datetime.date(2011, 10, 6))

    >>> get_date_range(DateRange.LastWeekSunSat)
    (datetime.date(2011, 9, 25), datetime.date(2011, 10, 1))

    >>> get_date_range(DateRange.LastWeekMonSun)
    (datetime.date(2011, 9, 26), datetime.date(2011, 10, 2))

    >>> get_date_range(DateRange.LastBusinessWeek)
    (datetime.date(2011, 9, 26), datetime.date(2011, 9, 30))

    >>> get_date_range(DateRange.Last14Days)
    (datetime.date(2011, 9, 22), datetime.date(2011, 10, 6))

    >>> get_date_range(DateRange.ThisMonth)
    (datetime.date(2011, 10, 1), datetime.date(2011, 10, 6))

    >>> get_date_range(DateRange.Last30Days)
    (datetime.date(2011, 9, 6), datetime.date(2011, 10, 6))

    >>> get_date_range(DateRange.LastMonth)
    (datetime.date(2011, 9, 1), datetime.date(2011, 9, 30))

    >>> get_date_range(DateRange.AllTime)
    (None, None)
    """
    
    today = d0 or datetime.now()
    week_ago = today - timedelta(7)
    last_week_monday = week_ago - timedelta(week_ago.weekday())
    one_day = timedelta(1)
    first_day_of_month = today - timedelta(today.day) + one_day
    first_day_of_prev_month = first_day_of_month - timedelta((first_day_of_month - one_day).day)
    d1, d2 = {
        DateRange.Today: (today, today),
        DateRange.Yesterday: (today - one_day, today - one_day),
        DateRange.ThisWeekSunToday: (today - timedelta(today.weekday() + 1), today),
        DateRange.ThisWeekMonToday: (today - timedelta(today.weekday()), today),
        DateRange.Last7Days: (today - timedelta(7), today),
        DateRange.LastWeekSunSat: (last_week_monday - one_day, last_week_monday + timedelta(5)),
        DateRange.LastWeekMonSun: (last_week_monday, last_week_monday + timedelta(6)),
        DateRange.LastBusinessWeek: (last_week_monday, last_week_monday + timedelta(4)),
        DateRange.Last14Days: (datetime.now() - timedelta(14), datetime.now()),
        DateRange.ThisMonth: (first_day_of_month, today),
        DateRange.Last30Days: (datetime.now() - timedelta(30), datetime.now()),
        DateRange.LastMonth: (first_day_of_prev_month, first_day_of_month - one_day),
        DateRange.AllTime: (None, None),
        DateRange.CustomDateRange: (d1, d2),
    }[range]
    if d1:
        d1 = d1.date()
    if d2:
        d2 = d2.date()
    return d1, d2


if __name__ == '__main__':
    import doctest
    doctest.testmod()