Django Template Filter for Humanize Day

rent_statistics.py

"""
DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE 
        Version 2, December 2004 

 Copyright (C) 2016 Adiyat Mubarak <adiyatmubarak@gmail.com> 

 Everyone is permitted to copy and distribute verbatim or modified 
 copies of this license document, and changing it is allowed as long 
 as the name is changed. 

            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE 
   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION 

  0. You just DO WHAT THE FUCK YOU WANT TO.
"""
from django import template


register = template.Library()


@register.filter
def statistics(value):
    """Convert given day integer to a string to be more human readable
    representation.
    Example:
        * 1     -> 1 Day
        * 30    -> 1 Month
        * 90    -> 3 Months
        * 366   -> 1 Year 1 Day
    """
    if value == 0:
        word = ''
    elif value <= 1:
        word = '%d Day' % value
    elif 1 < value < 30:
        word = '%d Days' % value
    elif value > 1 and value == 30:
        word = '%d Month' % (value / 30)
    elif value > 1 and 30 < value <= 365:
        month = value / 30
        days = statistics(value % 30)
        if month > 1:
            month_label = 'Months'
            word = '%s %s %s' % (month, month_label, days)
        else:
            month_label = 'Month'
            word = '%s %s %s' % (month, month_label, days)
    else:
        year = value / 365
        if year > 1:
            year_label = 'Years'
        else:
            year_label = 'Year'
        word = '%d %s %s' % (year, year_label, statistics(value % 365))
    return str(word).strip()

tests.py

import unittest

from rent_statistics import statistics


class CustomFilterTest(unittest.TestCase):

    def test_day_singular(self):
        result = statistics(1)
        self.assertEqual('1 Day', result)

    def test_day_plural(self):
        result = statistics(20)
        self.assertEqual('20 Days', result)

    def test_month_singular(self):
        result = statistics(30)
        self.assertEqual('1 Month', result)

    def test_month_singular_day_singular(self):
        result = statistics(31)
        self.assertEqual('1 Month 1 Day', result)

    def test_month_plural_day_singular(self):
        result = statistics(61)
        self.assertEqual('2 Months 1 Day', result)

    def test_month_plural_day_plural(self):
        result = statistics(98)
        self.assertEqual('3 Months 8 Days', result)

    def test_day_in_a_month(self):
        result = statistics(365)
        self.assertEqual('12 Months 5 Days', result)

    def test_year_singular(self):
        result = statistics(366)
        self.assertEqual('1 Year 1 Day', result)

    def test_everything_plural(self):
        result = statistics(366 * 2 + 60)
        self.assertEqual('2 Years 2 Months 2 Days', result)


if __name__ == '__main__':
    unittest.main()