How to stop loop until user inputs a keyword to stop?

Question

My code right now is in an infinite loop, displaying the menu choices for doughnuts. I want it so that the user selects as many doughnuts as they want until they input \"5\". <

Answer 1

tl;dr check the improved version at the bottom of the answer

You can use the second form of iter to conveniently loop over user input until a certain value is given, in that case 5.

def get_choice():
    while True:
        choice = input('> ')
        if choice in ('1', '2', '3', '4', '5'):
            return int(choice)
        else:
            print("Please enter a valid choice from 1-5.")

if __name__ ==  '__main__':
    print("Please select doughnuts from the following menu: ")
    print("1. Chocolate-dipped Maple Puff ($3.50 each)")
    print("2. Strawberry Twizzler ($2.25 each)")
    print("3. Vanilla Chai Strudel ($4.05 each)")
    print("4. Honey-drizzled Lemon Dutchie ($1.99)")
    print("5. No more doughnuts.")

    order = set(iter(get_choice, 5))

    print(order)

Example

Please select doughnuts from the following menu: 
1. Chocolate-dipped Maple Puff ($3.50 each)
2. Strawberry Twizzler ($2.25 each)
3. Vanilla Chai Strudel ($4.05 each)
4. Honey-drizzled Lemon Dutchie ($1.99)
5. No more doughnuts.
> 2
> 4
> 3
> 7
Please enter a valid choice from 1-5.
> 5
{2, 3, 4}

As you can see, this generated a set of orders which can then be used to request further inputs.

Use data structures

Although, using a bunch of elif statements is not optimal here because it adds a lot of repetition and is not very maintainable. Instead, you should use a list of dictionaries to store information specific to each donut.

    doughnuts = [
        {'name': 'Chocolate-dipped Maple Puff', 'price': 3.50},
        {'name': 'Stawberry Twizzler', 'price': 2.25},
        ...
    ]

Now, all the print above can be simplified like so.

    for i, doughnut in enumerate(doughnuts, start=1):
        print(f'{i}. {doughnut["name"]} (${doughnut["price"]} each)')
    print(f'{i + 1}. No more doughnuts.')

You should do the same for you arithmetic, when variable are highly related, their values should instead be stored together in a list or a dict.

receipt = [
    {
        **doughnuts[i],
        'qty': int(input(f'How many {doughnuts[i]["name"]} '))
    }
    for i in order
]

print(f"Here is your receipt: ")

for item in receipt:
    print("==========================================")
    print(f"{item['qty']} {item['name']}")
    print("==========================================")
    print(f"Total Cost: ${item['qty'] * item['price']:.2f}")

Example

1. Chocolate-dipped Maple Puff ($3.5 each)
2. Stawberry Twizzler ($2.25 each)
3. Vanilla Chai Strudel ($4.05 each)
4. Honey-drizzled Lemon Dutchie ($1.99 each)
5. No more doughnuts.
> 1
> 2
> 5
How many Stawberry Twizzler 2
How many Vanilla Chai Strudel 1
Here is your receipt: 
==========================================
2 Stawberry Twizzler
==========================================
Total Cost: $4.50
==========================================
1 Vanilla Chai Strudel
==========================================
Total Cost: $4.05

Final version

You then have a simplified version of you code. Shorter and more easy to maintain: to add doughnuts you simply need to update the initial list doughnuts.

doughnuts = [
    {'name': 'Chocolate-dipped Maple Puff', 'price': 3.50},
    {'name': 'Stawberry Twizzler', 'price': 2.25},
    {'name': 'Vanilla Chai Strudel', 'price': 4.05},
    {'name': 'Honey-drizzled Lemon Dutchie', 'price': 1.99}
]

def get_choice():
    allowed = map(str, range(1, len(doughnuts) + 2))
    while True:
        choice = input('> ')
        if choice in allowed:
            return int(choice)
        else:
            print("Please enter a valid choice.")

if __name__ == '__main__':
    for i, doughnut in enumerate(doughnuts, start=1):
        print(f'{i}. {doughnut["name"]} (${doughnut["price"]} each)')
    print(f'{i + 1}. No more doughnuts.')

    receipt = [
        {
            **doughnuts[i],
            'qty': int(input(f'How many {doughnuts[i]["name"]}'))
        }
        for i in set(iter(get_choice, 5))
    ]

    print(f"Here is your receipt: ")
    for item in receipt:
        print("==========================================")
        print(f"{item['qty']} {item['name']}")
        print("==========================================")
        print(f"Total Cost: ${item['qty'] * item['price']:.2f}")