def user_input():
    print('[1]: ASCII to Binary')
    print('[2]: Binary to ASCII')
    user_input = input('Please choose [1] or [2]: ')
    if user_input == ('1', '[1]'):
        #
    elif user_input == ('2', '[2]'):
        #
    else:
        print('Please enter a valid input...')
        user_input()

if user_input == ('1', '[1]'):
    pass
elif user_input == ('2', '[2]'):
    pass
else:
    print('Please enter a valid input...')
    user_input()