pz.py

def validate_input(subject, options, parse_func=lambda x: x):
    while True:
        try:
            x = parse_func(input(f'Enter {subject} ({"/".join(map(str, options))})\n>>> '))
            if x not in options: raise ValueError
            break
        except ValueError:
            print('Please enter a valid option')
    return x

def percent_str(a, b):
    return str(round(a / b * 100, 1)) + '%'

extra_topping_names = ['pepperoni', 'chicken', 'extracheese', 'mushrooms', 'spinach', 'olives']
topping_counts = [0 for i in range(6)]
total_ordered_pizzas = 0
total_topping_count = 0
while True:
    size = validate_input('pizza size', ['small', 'medium', 'large'], str.lower)
    base = validate_input('pizza base', ['thin', 'thick'], str.lower)
    extra_topping_count = validate_input('number of extra toppings', [0, 1, 2, 3], int)
    toppings = ['tomato', 'cheese']
    topping_options = extra_topping_names.copy()
    print('Default toppings: ' + ', '.join(toppings))
    for i in range(extra_topping_count):
        extra_topping = validate_input(f'extra topping {str(i+1)}', topping_options, str.lower)
        topping_options.remove(extra_topping)
        toppings.append(extra_topping)
    print(f'\nYour order is a {size} pizza with a {base} base')
    print('Your toppings are: ' + ', '.join(toppings))
    if input('\nEnter "confirm" to confirm your order: ').lower() == 'confirm':
        for i in range(6):
            if extra_topping_names[i] in toppings:
                topping_counts[i] += 1
        total_topping_count += extra_topping_count
        total_ordered_pizzas += 1
        print('\nYour order number is: ' + f'{total_ordered_pizzas:04d}')
    else:
        print('Order cancelled')
    if input('Enter "end" to end day: ').lower() == 'end': break
if total_ordered_pizzas == 0:
    print('No pizzas ordered today')
elif total_ordered_pizzas == 0:
    print('No extra toppings ordered today')
else:
    max_topping_count = max(topping_counts)
    min_topping_count = min(topping_counts)
    popular_toppings = [extra_topping_names[i] for i in range(6) if topping_counts[i] == max_topping_count]
    unpopular_toppings = [extra_topping_names[i] for i in range(6) if topping_counts[i] == min_topping_count]

    print(' - '.join(['\nMost popular topping' +
                      ('s' if len(popular_toppings) > 1 else ''),
                      ', '.join(popular_toppings),
                      percent_str(max_topping_count, total_topping_count)]))
    print(' - '.join(['Least popular topping' +
                      ('s' if len(unpopular_toppings) > 1 else ''),
                      ', '.join(unpopular_toppings),
                      percent_str(min_topping_count, total_topping_count)]))