Python错误TypeError：+不支持的操作数类型：'function'和'function'

Question

I know there is some stuff online about this error but whatever I try just doesn't seem to fix it. I just started learning Python yesterday and am an absolute beginner so please don't judge my script. It is just a simple script wanting to take the order of a customer from a restaurant and just calculate the total price of the meal. It's pretty cheesy but I would love some help. I can not get my script to calculate the total cost of the meal and whatever I try, it just doesn't work. Could you please tell me what I am doing wrong and how to calculate the total cost of the meal based on what the customer chooses. Also If they pick an item that is not on the menu, the program closes instead of letting them try again. Why? I would greatly appreciate your help. :) THANKS

Here is a picture of the cost error I get when running the script in terminal.

Here is a picture of what I get if I type something that is not on the menu.

Here is my script.

Note, I have aded the items from the menu just to show you what they are and their cost.

    Apple = 3
    Banana = 4
    Kiwi = 2
    Peach = 5
    Hamburger = 12
    Parma = 22
    Steak = 24
    Sandwhich = 10
    Cream = 3
    Cake = 8
    Moose = 2
    Soda = 3
    Beer = 8
    Wine = 12


    def Fruit():
        print("Welcome to The Buttler's Pantery")
        Fruit = raw_input("what fruit would you like today?")

        if (Fruit == "Apple"):
            Main()
        elif (Fruit == "Banana"):
            Main()
        elif (Fruit == "Kiwi"):
            Main()
        elif (Fruit == "Peach"):
            Main()
        else:
            print("Sorry, but it appears that the item you have ordered is not on the menu")

    def Main():
        Main = raw_input("what Main would you like today?")

        if (Main == "Hamburger"):
            Dessert()
        elif (Main == "Parma"):
            Dessert()
        elif (Main == "Steak"):
            Dessert()
        elif (Main == "Sandwhich"):
            Dessert()
        else:
            print("Sorry, but it appears that the item you have ordered is not on the menu")


    def Dessert():
        Dessert = raw_input("what Dessert would you like today?")

        if (Dessert == "Cream"):
            Beverage()
        elif (Dessert == "Cake"):
            Beverage()
        elif (Dessert == "Moose"):
            Beverage()
        else:
            print("Sorry, but it appears that the item you have ordered is not on the menu")

    def Beverage():
        Beverage = raw_input("what Beverage would you like today?")

        if (Beverage == "Soda"):
            print(add(num1, num2, num3, num4))
        elif (Beverage == "Beer"):
            print(add(num1, num2, num3, num4))
        elif (Beverage == "Wine"):
            print(add(num1, num2, num3, num4))

        else:
            print("Sorry, but it appears that the item you have ordered is not on the menu")

    def add(num1, num2, num3, num4):
        return num1 + num2 + num3 + num4

    def num1():
        if (Fruit == "Apple"):
            num1 = 3
        elif (Fruit == "Banana"):
            num1 = 4    
        elif (Fruit == "Kiwi"):
            num1 = 2    
        elif (Fruit == "Peach"):
            num1 = 5
        else: num1 = 0

    def num2():
        if (Main == "Hamburger"):
            num2 = 12
        elif (Main == "Parma"):
            num2 = 22
        elif (Main == "Steak"):
            num2 = 24
        elif (Main == "Sandwhich"):
            num2 = 10
        else: num2 = 0

    def num3():
        if (Dessert == "Cream"):
            num3 = 3
        elif (Dessert == "Cake"):
            num3 = 8
        elif (Dessert == "Moose"):
            num3 = 2
        else: num3 = 0

    def num4():
        if (Beverage == "Soda"):
            num4 = 3
        elif (Beverage == "Beer"):
            num4 = 8
        elif (Beverage == "Wine"):
            num4 = 12   
        else: num4 = 0









    Fruit()

Answer 1

You are redifining your function names with your local variable names

No wonder why there is a mixup.

I know visual basic uses to do that for return values but you cannot do that in python.

Just rename your local variables (the ones assigned to result of raw_input and it will be ok

Answer 2

You shouldn't name functions the same as variables, ie the fruit function should look like this:

def Fruit():
    print("Welcome to The Buttler's Pantery")
    global fruit
    fruit = raw_input("what fruit would you like today?")

    if (fruit == "Apple"):
        Main()
    elif (fruit == "Banana"):
        Main()
    elif (fruit == "Kiwi"):
        Main()
    elif (fruit == "Peach"):
        Main()
    else:
        print("Sorry, but it appears that the item you have ordered is not on the menu")
        Fruit()

Also note the global , it makes fruit accesable outside the function Fruit() . If you'd apply these changes to all functions, it should work

If you also want to let people try again, you could simply call the function again, like in the function Fruit() .

Hope this helps!

Answer 3

You used functions to define num1,num2... values , which becomes local variables . whereas you should have made these variables out of function . And use those variables in other functions using the keyword 'global'.

here's the edited code :

Apple = 3
Banana = 4
Kiwi = 2
Peach = 5
Hamburger = 12
Parma = 22
Steak = 24
Sandwhich = 10
Cream = 3
Cake = 8
Moose = 2
Soda = 3
Beer = 8
Wine = 12
num1 = 0
num2 = 0
num3 = 0
num4 = 0


def Fruit():
    global num1
    print("Welcome to The Buttler's Pantery")
    Fruit = raw_input("what fruit would you like today?")

    if (Fruit == "Apple"):
        num1 = 3
        Main()
    elif (Fruit == "Banana"):
        num1 = 4
        Main()
    elif (Fruit == "Kiwi"):
        num1 = 2
        Main()
    elif (Fruit == "Peach"):
        num1 = 5
        Main()
    else:
        print("Sorry, but it appears that the item you have ordered is not on the menu")

def Main():
    global num2
    Main = raw_input("what Main would you like today?")

    if (Main == "Hamburger"):
        num2 = 12
        Dessert()
    elif (Main == "Parma"):
        num2 = 22
        Dessert()
    elif (Main == "Steak"):
        num2 = 24
        Dessert()
    elif (Main == "Sandwhich"):
        num2 = 10
        Dessert()
    else:
        print("Sorry, but it appears that the item you have ordered is not on the menu")


def Dessert():
    global num3
    Dessert = raw_input("what Dessert would you like today?")

    if (Dessert == "Cream"):
        num3 = 3
        Beverage()
    elif (Dessert == "Cake"):
        num3 = 8
        Beverage()
    elif (Dessert == "Moose"):
        num3 = 2
        Beverage()
    else:
        print("Sorry, but it appears that the item you have ordered is not on the menu")

def Beverage():
    global num1
    global num2
    global num3
    global num4
    Beverage = raw_input("what Beverage would you like today?")

    if (Beverage == "Soda"):
        num4 = 3
        print(add(num1,num2,num3,num4))
    elif (Beverage == "Beer"):
        num4 = 8
        print(add(num1,num2,num3,num4))
    elif (Beverage == "Wine"):
        num4 = 12
        print(add(num1,num2,num3,num4))

    else:
        print("Sorry, but it appears that the item you have ordered is not on the menu")


def add(a,b,c,d) :
    return a+b+c+d



Fruit()