Vfrdtyky

I'm just starting to learn Python and am having trouble getting my GUI to work with my application. Here's what I want it it do:

1) User inputs String < 100 characters into textbox

2) Program slices 5 characters at a time from String and counts how many of letter "A" and "B" there are in substring

3) Program prints 5-character substring and # of each letter to GUI textbox

Here's what I have so far:

from tkinter import *

from tkinter.ttk import *



class App(Frame):



    def __init__(self):

        super().__init__()



        # Global variables

        self.input_text = StringVar

        self.output_text = StringVar

        self.letter_A = 0

        self.letter_B = 0

        self.launchGUI()



    def launchGUI(self):

        self.button_selected_string = StringVar()

        self.pack(fill=BOTH, expand=True)



        self.topFrame = Frame(self)

        self.topFrame.grid(row=0)

        self.bottomFrame = Frame(self)

        self.bottomFrame.grid(row=2)



        # Input textbox

        self.input_textbox = Text(self.topFrame, height=5, width=50, borderwidth=2, relief=RIDGE)

        self.input_textbox.grid(row=1)



        # Output textbox

        self.output_textbox = Text(self.bottomFrame, height=5, width=50, borderwidth=2, relief=RIDGE)

        self.output_textbox.grid(row=2)



        # Submit button

        self.submitButton = Button(self.bottomFrame, text="Submit", width=30, command=self.print_result)

        self.submitButton.grid(row=1)



        # Radio button

        self.radioButton1 = Radiobutton(self.bottomFrame, text="Name of Button", variable=self.button_selected_string,

                                        value="BUTTON_SELECTED",

                                        command=self.get_button_state)

        self.radioButton1.grid(row=0)



    # Function for printing result in textbox

    def print_result(self):

        self.iterate() # Calls another method

        self.output_textbox.insert("1.0", str(self.output_text) + str(self.letter_A) + str(self.letter_B))



    # Function that retrieves result of user selection and stores as String

    def get_button_state(self):

        self.button_selected_string.get()



    def iterate(self):

        temp = self.input_textbox.get("1.0", "end-1c")

        if self.get_button_state() == "BUTTON_SELECTED": # Will always be selected for the purpose of example

            i = 100

            while i > 20:

                temp = temp[(i - 5):i]

                self.output_text = self.count_letters(temp)

                i = i - 1

        return self.output_text



    def count_letters(self):



        for y in self.output_text:

            for x in y:

                if x == 'A' or x == 'a':

                    self.letter_A += 1

                elif x == 'B' or x == 'b':

                    self.letter_B += 1

        return self.output_text



def main():

    root = Tk()

    root.geometry("350x300+300+300")

    app = App()

    root.mainloop()





if __name__ == '__main__':

    main()

The problem (among many, I'm sure) is that when I try and print the results, instead of getting a list of 5-character long substrings and the number of letters "A" and "B", I just get:

<class 'tkinter.StringVar'>00

It seems like I have a type error and am probably messing up with the scope of my variables, but I'm not sure how to proceed...

Any help would be GREATLY appreciated!