Calculate if you are resident or not

resident_days.py

from datetime import datetime, timedelta
from functools import lru_cache

CALC_START = '01.01.2021'
CALC_END = '01.01.2024'
TRIPS = [
    ('08.03.2022', '03.04.2022'),
    ('01.10.2022', '15.10.2022'),
    ('15.10.2022', None),
]

DATE_FORMAT = '%d.%m.%Y'
RESIDENT_DAYS = 183


@lru_cache(maxsize=1000)
def is_trip(day):
    for trip_start, trip_end in TRIPS:
        if (trip_start <= day) and ((day < trip_end) if trip_end else True):
            return True
    return False


def calc_days_at_home(start, end):
    days_at_home = 0
    while start <= end:
        days_at_home += not is_trip(start)
        start += timedelta(days=1)

    return days_at_home


def main():
    print(f'Calc boundaries: {CALC_START} - {CALC_END}')
    calc_start = datetime.strptime(CALC_START, DATE_FORMAT)
    calc_end = datetime.strptime(CALC_END, DATE_FORMAT)

    for i, trip in enumerate(TRIPS):
        trip_start, trip_end = trip
        print(f' - trip {i + 1}: {trip_start} - {trip_end or "current"}')
        trip_start = datetime.strptime(trip_start, DATE_FORMAT)
        trip_end = datetime.strptime(trip_end, DATE_FORMAT) if trip_end else None
        TRIPS[i] = (trip_start, trip_end)

    start = calc_start
    while True:
        end = start.replace(year=start.year + 1)
        days_at_home = calc_days_at_home(
            start=start,
            end=end,
        )

        if days_at_home < RESIDENT_DAYS:
            print(f'\nResidence expire at {end.strftime(DATE_FORMAT)}')
            break
        elif start == calc_end:
            print('\nResidence would not expire in these boundaries!')
            break
        else:
            start += timedelta(days=1)


if __name__ == '__main__':
    main()