Python vending machine snacks and drinks

Question

Hi guys I have been trying to create a working python vending machine for over a month now and it doesn't look like I am making any progress. If somebody could help me that could be great :) Here is my program so far:

print ("Welcome to the Vending Machine\n")

total = 0
dr = 1
sn = 3
money=int(input("How much money do you want to insert"))
print ("Prices: Drinks: £1, Snacks: £3\n")
Drinks = {'Coke','Pepsi','Orange Juice', 'Apple Juice','Water'}
Snacks = {'Chocolate', 'Snickers','Twix','Peanuts','Crisp'}

state = 'subtotal'
while total <= money:
    if state != 'total':
    print('')
    print('')
    print ("\nDrinks Menue:")
    print(Drinks)
    print ("Snacks Menue:")
    print(Snacks)
    choice = input("\nEnter the item of your choice: ")
    if choice in Drinks: 
        total += dr
    elif choice in Snacks:
        total += sn
    else:
        state = 'total'
    print("\n\nThat will be a",state,"of £",total)
else:
    print("You have exceeded your inserted money good bye")

I'm trying to make the code reject invalid input and stop when the user has gone over his spending limit.

What have you tried doing and how specifically did it fail? Post some examples, full error messages, etc. — Daenyth, May 21 '14 at 18:32
You may find [Asking the user for input until he gives a valid response](http://stackoverflow.com/questions/23294658/asking-the-user-for-input-until-he-gives-a-valid-response) to be useful. — Kevin, May 21 '14 at 18:33
I'm kind of intrigued by this. I think I'll work up an OOP answer in the next hour or so. — Adam Smith, May 21 '14 at 18:49

score 2 · Answer 1 · answered May 21 '14 at 18:54

There is only one problem with this when I run this. So, here is the fix with some explanation so you can learn something. It may seem like a simple mistake but we all make them at some point and eventually, indenting will be second nature.

Indents

Unlike some langues, in Python the indentation matters. A lot. Let's look at your first if statement.

    if state != 'total':
    print('')
    print('')
    print ("\nDrinks Menue:")
    print(Drinks)
    print ("Snacks Menue:")
    print(Snacks)
    choice = input("\nEnter the item of your choice: ")

Can you see the problem? After an if statment, or more precisely, after the :, we need to indent everything else that we want to be carried out by the if statement otherwise Python won't know where to stop! So by making this simple change:

if state != 'total':
    print('')
    print('')
    print ("\nDrinks Menue:")
    print(Drinks)
    print ("Snacks Menue:")
    print(Snacks)

We have no more error and your program now runs. Notice the indents? Just check that they are always right.

To add on to this answer, you want your indentation to be consistent throughout your entire file. If you have a tab in one place, and spaces in another, Python won't know where one indented block starts and ends. Common convention in python is to use 4 spaces (and many editors can be configured to convert tabs to spaces). — limasxgoesto0, May 21 '14 at 20:15

Python vending machine snacks and drinks

1 Answers1