python list using inputs

Question

i am making a pizza ordering system for a project, the user chooses how many pizzas they want with this:

pizza_number=0
goodpizza_number=False 
while not goodpizza_number:
    try:
        pizza_number= int(input("How many Pizzas do you want? (MAX 5): "))
        if pizza_number ==0 or pizza_number > 5:
            print("Not a correct choice, Try again")
        else:
            goodpizza_number=True 
    except ValueError:
        print("Not a number, Try again")

and then there is a list of pizzas for the user:

PIZZA_LIST=["Tandoori chicken: $8.50", "Prawn: $8.50", "Ham and cheese: $8.50", "Pepperoni: $8.50", "Hawaiian: $8.50","Beef and onion: $8.50","Meat lovers: $8.50", "Satay chicken: $13.50", "Apricot chicken: $13.50", "Supreme cheese:13.50", "Italian beef: $13.50", "Mediterraneo: $13.50"]
for index in range(0, len(PIZZA_LIST)):
    print(index, PIZZA_LIST[index])

and the user is able to choose what pizzas they want with this:

pizza=[] 
for n in range(pizza_number): #covers values from 0 to 9 
    pizza = pizza + [int(input("Choose a pizza: "))] 
print(pizza) 

The first 7 pizzas on the list have to be $8.50 and the last 5 pizzas on the list have to be $13.50. how can i add the user's choices together and get the prices of all the pizzas they chose and add to the total cost?

Answer 1

First, you might want to change how the pizza names and prices are presented. Since you get user input as integer, I would suggest using list of tuples:

pizzas_with_prices = [('Tandoori chicken', 8.5), ('Prawn', 8.5) ..., ('Mediterraneo', 13.5)]

then you can loop over your pizza list (which could be better named as selected_pizzas or so):

total_price = 0
for selected in selected_pizzas:
  total_price += pizzas_with_prices[selected][1]
print total_price

Also, couple of suggestions to improve the code:

For the first code block, you can get rid of the goodpizza_number

number_of_pizzas = 0
while 0 < number_of_pizzas <= 5:
  try:
    number_of_pizzas = int(input("How many Pizzas do you want? (MAX 5): "))
  except ValueError:
    print("Not a number, try again")

On the second block, as suggested, you could use list of tuples and use enumerate

pizzas_with_prices = [('Tandoori chicken', 8.5), ('Prawn', 8.5) ..., ('Mediterraneo', 13.5)]
for index, pizza in enumerate(pizzas_with_prices):
  print("%d %s: $%s" % (index, pizza[0], pizza[1]))

Answer 2

You need to create another pizza name and pizza price in a dict. The user choice of pizza can be put in a list. Once you have the list, iterate over the list to get price from pizza name-price dict and add then to get total price.

Answer 3

total_cost = sum([float(PIZZA_LIST[idx].split('$')[1]) for idx in pizza])

By the way: you can replace

pizza = pizza + [int(input("Choose a pizza: "))] 

with

pizza.append(int(input("Choose a pizza: ")))