Python Date

date_service.py

import datetime
from service.time_converter import iso_format_to_unix_time


DAYS_OF_THE_WEEK = 7


def current_week_start(of = None):
    date_to_compare = datetime.datetime.now()

    if of is not None:
        date_to_compare = datetime.datetime.utcfromtimestamp(of)

    current_weekday_starting_in_one = date_to_compare.weekday() + 1

    sunday_time_delta = datetime.timedelta(
        current_weekday_starting_in_one % DAYS_OF_THE_WEEK
    )

    sunday = date_to_compare - sunday_time_delta
    sunday_without_time = sunday.date()

    return iso_format_to_unix_time(sunday_without_time.isoformat())


def previous_week_start(of = None):
    current_sunday = datetime.datetime.utcfromtimestamp(current_week_start(of))
    previous_sun = (current_sunday - datetime.timedelta(DAYS_OF_THE_WEEK)).date()

    return iso_format_to_unix_time(previous_sun.isoformat())

test_date_service.py

from service.date_service import current_week_start, previous_week_start
from unittest import TestCase
from service.time_converter import iso_format_to_unix_time
import datetime


class TestDateService(TestCase):
    def test_it_returns_the_previous_week_start(self):
        previous_week = previous_week_start(iso_format_to_unix_time('2021-08-23T08:55:00'))
        self.assertEqual(previous_week, iso_format_to_unix_time(datetime.date(2021, 8, 15).isoformat()))
        self.assertTrue(previous_week_start() < iso_format_to_unix_time(datetime.datetime.today().isoformat()))

    def test_it_returns_the_current_week_start(self):
        current_week = current_week_start(iso_format_to_unix_time('2021-08-23T08:55:00'))
        self.assertEqual(current_week, iso_format_to_unix_time(datetime.date(2021, 8, 22).isoformat()))
        self.assertTrue(current_week_start() < iso_format_to_unix_time(datetime.datetime.today().isoformat()))