01. Day of Week

num = int(input())

if num == 1:
    print('Monday')
elif num == 2:
    print('Tuesday')
elif num == 3:
    print('Wednesday')
elif num == 4:
    print('Thursday')
elif num == 5:
    print('Friday')
elif num == 6:
    print('Saturday')
elif num == 7:
    print('Sunday')
else:
    print('Error')


Фундаменталс решения:)

Решение с масив и тернарен оператор:

num = int(input())

day_of_week = ["Error", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday"]

print(day_of_week[num if 0 < num < 8 else 0])


Решение с речник и тернарен оператор:

num = int(input())

day_of_week = {
    1: 'Monday',
    2: 'Tuesday',
    3: 'Wednesday',
    4: 'Thursday',
    5: 'Friday',
    6: 'Saturday',
    7: 'Sunday'
}

print(f'{day_of_week[num]}' if 0 < num < 8 else 'Error')