How do I store the information of checkboxes? And how do i use the info in another variable?

Question

i was hoping you would help me with the following code and tell me where im going wrong. I am not that experienced in python so help would be great! Heres my code:

from Tkinter import *

import math
from math import *

import tkFont
import tkMessageBox

numberOfIngredients = {}
diameter = {}

class Application(Frame):
    """ GUI application that creates a story based on user input. """
    def __init__(self, master):
        """ Initialize Frame. """
        #Make size later master.geometry("485x280+5+10")
        Frame.__init__(self, master)
        self.grid()
        self.create_widgets()
        self.config(bg = "#a6b6cb")

    def create_widgets(self):
        """ Define the widgets and positioning within the frame. """
        #Display the Title
        Label(self, text = "Hamburger Calculator", font = ("Calibri", "25"), bg = "#a6b6cb", fg = "#17375e").grid(row = 0, column = 1, sticky = W)

        #Instructions For Selecting Box
        Label(self, text ="Select your extra ingredients:",
              bg = "#a6b6cb").grid(row = 1, column =1, sticky = W)

        #Button To Calculate
        Button(self, text = "Calculate Cost",  bg = "#92d050",
               command = self.calculate,
               font = ("Calibri", "12")).grid(row = 6, column = 1, sticky = SE)

        #Button To Quit
        Button(self, text = "Quit", bg = "#913c3a",
               command = self.quit,
               font = ("Calibri", "12")).grid(row = 7, column = 1,
                                              sticky = SE)

        #Radio Box For Patty Size
        Label(self, text ="Hamburger Size:",
              bg = "#a6b6cb").grid(row = 1, column = 0, sticky = W)

        diameter = IntVar()

        Radiobutton(self,
                    text = "10 cm",
                    bg = "#a6b6cb",
                    variable = diameter,
                    value = 10,
                    ).grid(row = 3, column = 0, sticky =W)

        Radiobutton(self,
                    text = "20 cm",
                    bg = "#a6b6cb",
                    variable = diameter,
                    value = 20,
                    ).grid(row = 4, column = 0, sticky =W)

        Radiobutton(self,
                    text = "35 cm",
                    bg = "#a6b6cb",
                    variable = diameter,
                    value = 35,
                    ).grid(row = 5, column = 0, sticky =W) 


        #Check Box for Cheese
        self.cheese = BooleanVar()
        Checkbutton(self,
                    text="Cheese",
                    bg = "#a6b6cb",
                    variable = self.cheese,
                    onvalue="yes", offvalue="no"
                    ).grid(row =3,
                    column = 1, sticky =W)
        #Check Box for Mushrooms
        self.mushroom = BooleanVar()
        Checkbutton(self,
                    text="Mushrooms",
                    bg = "#a6b6cb",
                    variable = self.mushroom,
                    onvalue="yes", offvalue="no"
                    ).grid(row =4,
                    column = 1, sticky =W)
        #Check Box for Onions
        self.onion = BooleanVar()
        Checkbutton(self,
                    text="Onions",
                    bg = "#a6b6cb",
                    variable = self.onion,
                    onvalue="yes", offvalue="no"
                    ).grid(row =5,
                    column = 1, sticky =W)
        #Check Box for Extra Beefburger
        self.beefburger = BooleanVar()
        Checkbutton(self,
                    text="Extra Burger Patty",
                    bg = "#a6b6cb",
                    variable = self.beefburger,
                    onvalue="yes", offvalue="no"
                    ).grid(row =6,
                    column = 1, sticky =W)

        numberOfIngredients = 0

        if self.cheese.get() == "yes":
            numberOfIngredients + 1
        if self.mushroom.get() == "yes":
            numberOfIngredients + 1
        if self.onion.get() == "yes":
            numberOfIngredients + 1
        if self.beefburger.get() == "yes":
            numberOfIngredients + 1


    def calculate(self):
        #Constants and Variables
        fixedCost = 3.75
        baseCost = 1.55
        extraCost = 1.25

        global numberOfIngredients
        global diameter

        #Formulas
        area = (pi * sqrt(int(diameter) / 100) ) / 4
        cost = fixedCost + (baseCost * area) + (numberOfIngredients * extraCost)
        totalCost = 1.5 * cost

        #Message Box
        tkMessageBox.showinfo(
            title="Total Cost",
            message="The total cost of the hamburger is $" + str(diameter))


#Main
root = Tk()
root.title("Hamburger Calculator")
app = Application(root)
root.mainloop()
root.destroy()

Here is the error i get at the moment:

Exception in Tkinter callback Traceback (most recent call last): File "C:\Python27\lib\lib-tk\Tkinter.py", line 1410, in call return self.func(*args) File "C:\Users\Matt Sharp\Desktop\Assessment For Hamburgers v2tester.py", line 131, in calculate area = (pi * sqrt(int(diameter) / 100) ) / 4 TypeError: int() argument must be a string or a number, not 'dict'

As well as this error, i know that my diameter and numberOfIngredients isn't working.

Answer 1

This is a really good example of why you should avoid globals for storing your state...

At the top of your module you create diameter as a dictionary:

diameter = {}

Then in your create_widgets() method, you create a local variable diameter to be used in your widgets (though you never keep a reference to it):

diameter = IntVar() 

But then in your calculate() method, you refer to the global diameter (which is a dict) and use it in a math expression as if it were an int:

area = (pi * sqrt(int(diameter) / 100) ) / 4

You also do a similar thing with numberOfIngredients. It is created as a global dict, but used as a local int and not saved, and then referred to as a global again in a math expression.

# global numberOfIngredients is {}
cost = fixedCost + (baseCost * area) + (numberOfIngredients * extraCost)

globals can easily make your application confusing because you cannot always identify the origin of the variable based on current scope.

I am not sure how you expect to use the global dict vs the local int, but ultimately the variables should be maintained on the class as instance attributes:

class Application(Frame):
    def __init__(self, master): 
        ...
        self.diameter = IntVar()
        self.numberOfIngredients = 0

    def create_widgets(self):
        ...
        Radiobutton(self,
                    text = "10 cm",
                    bg = "#a6b6cb",
                    variable = self.diameter,
                    value = 10,
                    ).grid(row = 3, column = 0, sticky =W)
        ...
        if self.cheese.get() == "yes":
            self.numberOfIngredients += 1

    def calculate(self):
        ...
        area = (pi * sqrt(int(self.diameter) / 100) ) / 4
        cost = fixedCost + (baseCost * area) + \
                    (self.numberOfIngredients * extraCost)