Untitled

from datetime import datetime, timedelta

start_time = datetime.strptime('09:00', '%H:%M')
end_time = datetime.strptime('22:00', '%H:%M')

busy = [
    {'start': '10:30', 'stop': '10:50'},
    {'start': '18:40', 'stop': '18:50'},
    {'start': '14:40', 'stop': '15:50'},
    {'start': '16:40', 'stop': '17:20'},
    {'start': '20:05', 'stop': '20:20'}
]

busy_intervals = []
for interval in busy:
    start = datetime.strptime(interval['start'], '%H:%M')
    stop_time = datetime.strptime(interval['stop'], '%H:%M')
    busy_intervals.append((start, stop_time))


def _is_busy_time(start_t: datetime, busy_frame: tuple[datetime, datetime]) -> bool:
    stop_t = start_t + timedelta(minutes=30)
    if busy_frame[0] <= stop_t <= busy_frame[1]:
        return True
    elif start_t <= busy_frame[0] <= stop_t:
        return True
    elif start_t == busy_frame[0]:
        return True
    return False


free_windows = []
current_time = start_time
while current_time + timedelta(minutes=30) < end_time:

    # Заполним время с учётом занятых окон
    for frame in sorted(busy_intervals, key=lambda x: x[0]):
        while not _is_busy_time(current_time, frame):
            stop_time = current_time + timedelta(minutes=30)
            free_time = {'start': current_time, 'stop': stop_time}
            free_windows.append(free_time)
            current_time = stop_time
        current_time = frame[1]

    # Заполним оставшееся рабочее время
    while current_time + timedelta(minutes=30) < end_time:
        stop_time = current_time + timedelta(minutes=30)
        free_time = {'start': current_time, 'stop': stop_time}
        free_windows.append(free_time)
        current_time = stop_time

# Вывод списка свободных окон
for window in free_windows:
    print(f'Doctor`s free time is: {window["start"].strftime("%H:%M")} -- {window["stop"].strftime("%H:%M")}')