Need help understanding why my code doesn't run [python]

Question

So my goal is to make an ordering system for a cafe with various types of coffee available. Right now I'm having trouble understanding why my code doesn't run, whenever I execute the code nothing happens and I'm not sure why

class Coffee(object):

    def __init__(self,name):
        self.name = name

    def coffee (self, coffee_type, price):
        self.coffee_type = coffee_type
        self.price = price

class Order(object):

    def __init__(self, name):
        self.name = name

    def newOrder (self, coffee_type, coffee_amount):
        this.coffee_type = coffee_type
        this.coffee_amount = coffee_amount




class Main(object):

    def __init__ (self, name):
        self.name = name


    from Coffee import coffee

    flat_white = coffee("1 : Flat White", 3.50)
    long_black = coffee("2 : Long Black", 3.50)
    cappuccino = coffee("3 : Cappuccino", 4.00)
    espresso = coffee("4 : Espresso", 3.25)
    latte = coffee("5 : Latte", 3.50)

    Ordering = 'Y'

    while Ordering == 'Y':
        try:
            order_coffee = int(input("What coffee would you like to order?", pprint (vars(coffee))))
            break

        except:
            ValueError
            print ("wrong input")

        order_amount = input("How many would you like to order?")

        if order_coffee == 1:
            new_Order(flat_white, order_amount)

        elif order_coffee == 2:
            new_Order(long_black, order_amount)

        elif order_coffee == 3:
            new_Order(cappuccino, order_amount)

        elif order_coffee == 4:
            new_Order(espresso, order_amount)

        elif order_coffee == 5:
            new_Order(latte, order_amount)

        else:
            print ("Please enter a valid number")
            break

Answer 1

It looks like there are several issues with your code. I will try to help you out with a couple.

First, no need for the __init__ method to accept a name. Just make the method accept the necessary information for the object:

class Coffee(object):
    def __init__ (self, coffee_type, price):
        self.coffee_type = coffee_type
        self.price = price

class Order(object):
    def __init__(self, coffee_type, coffee_amount):
        self.coffee_type = coffee_type
        self.coffee_amount = coffee_amount

Second, since it does not really do anything, you can replace the Main class to an execution in a conditional as is typically seen in Python programs/scripts:

if __name__ =="__main__":
    ... # put main code here

Next, the except as it is written will catch all exceptions making debugging more difficult. If you only want to catch the ValueError, do:

    except ValueError:
        print ("wrong input")

If you use the current flow (i.e. with the try except block, you should put all of the order logic within the try block as it does not make any sense outside. Also, the necessary variables needed (order_coffee) will not be defined if you have a ValueError.

Adding a break after accepting the order input will cause you to break out of the ordering loop after an order is entered. This is probably not intended behavior. No break is needed here. Ditto for after outputting "Please enter a valid number".

When creating an Order, you just need to call Order(coffee_type, coffee_amount). When you create this order, make sure to set it to a variable too. probably something like:

new_order = Order(flat_white, order_amount)

Printing "Please enter a valid number" and "wrong input" is slightly redundant. You only need one of them to print under invalid input.

Lastly, pprint will print stuff out then return None so print(..., pprint(x)) will print an extra None once it has finished pretty printing x, instead just call pprint as if it was another call to print.

-- --

Making all of these changes, you will end up with something like:

class Coffee(object):

    def __init__ (self, coffee_type, price):
        self.coffee_type = coffee_type
        self.price = price

class Order(object):

    def __init__(self, coffee_type, coffee_amount):
        self.coffee_type = coffee_type
        self.coffee_amount = coffee_amount

if __name__ =="__main__":

    coffee_available=[Coffee("1 : Flat White", 3.50), 
                      Coffee("2 : Long Black", 3.50), 
                      Coffee("3 : Cappuccino", 4.00), 
                      Coffee("4 : Espresso", 3.25), 
                      Coffee("5 : Latte", 3.50)]

    ordering = 'Y'

    while ordering == 'Y':

        print("Coffee Type\t\tPrice")
        print("-----------\t\t-----")
        for coffee in coffee_available:
            print("{}\t- - -\t$ {}".format(coffee.coffee_type,coffee.price))
        print()
        order_coffee = int(input("What is the number of the coffee you want? "))

        order_amount = input("How many would you like to order? ")

        new_order = None

        if order_coffee >= 1 and order_coffee <=5:
            new_order = Order(coffee_available[order_coffee-1], order_amount)

        else:
            print ("Please enter a valid number")