Dice Roll DnD Stat Chooser

import tkinter as tk
import tkinter.simpledialog as sdg
import tkinter.messagebox as mbx
import tkinter.font as tkf
import random as rnd

class diceRollStatsRoot(sdg.Dialog):
    def body(self, master):
        self.title("New Character: Dice Roll Stats")
        self.resizable(False, False)
        self.letters = ('A', 'B', 'C', 'D', 'E', 'F')
        self.rolled = False
        self.rolls = [0, 0, 0, 0, 0, 0]
        self.rollsVar = tk.StringVar()
        self.rollsVar.set("Press \"Roll\" to begin!")

        tk.Label(master, text = "Set each stat to a unique lettered value", font = ftSmall).grid(row = 0, columnspan = 3)

        rollsLbl = tk.Label(master, textvariable = self.rollsVar, width = 36, relief = "ridge", font = ftNormal)
        rollsLbl.grid(row = 1, column = 0, columnspan = 2)

        tk.Button(master, text = "Roll", command = self.rollStats, cursor = "hand2", font = ftNormal).grid(row = 1, column = 2)

        tk.Label(master, text = "Strength", font = ftNormal).grid(row = 2, column = 0)
        tk.Label(master, text = "Dexterity", font = ftNormal).grid(row = 3, column = 0)
        tk.Label(master, text = "Constitution", font = ftNormal).grid(row = 4, column = 0)
        tk.Label(master, text = "Intelligence", font = ftNormal).grid(row = 5, column = 0)
        tk.Label(master, text = "Wisdom", font = ftNormal).grid(row = 6, column = 0)
        tk.Label(master, text = "Charisma", font = ftNormal).grid(row = 7, column = 0)

        self.STRSbx = tk.Spinbox(master, values = self.letters)
        self.DEXSbx = tk.Spinbox(master, values = self.letters)
        self.CONSbx = tk.Spinbox(master, values = self.letters)
        self.INTSbx = tk.Spinbox(master, values = self.letters)
        self.WISSbx = tk.Spinbox(master, values = self.letters)
        self.CHASbx = tk.Spinbox(master, values = self.letters)

        self.STRSbx.grid(row = 2, column = 1, columnspan = 2)
        self.DEXSbx.grid(row = 3, column = 1, columnspan = 2)
        self.CONSbx.grid(row = 4, column = 1, columnspan = 2)
        self.INTSbx.grid(row = 5, column = 1, columnspan = 2)
        self.WISSbx.grid(row = 6, column = 1, columnspan = 2)
        self.CHASbx.grid(row = 7, column = 1, columnspan = 2)


    def validate(self):
        if not self.rolled:
            mbx.showerror("Error", "You must roll at least once!")
            return 0

        selections = []
        selections.append(self.STRSbx.get())
        selections.append(self.DEXSbx.get())
        selections.append(self.CONSbx.get())
        selections.append(self.INTSbx.get())
        selections.append(self.WISSbx.get())
        selections.append(self.CHASbx.get())

        for l in self.letters:
            if selections.count(l) > 1:
                mbx.showerror("Error", "Each lettered value must be used, and used only once!")
                return 0

        return 1

    def apply(self):
        resultString = ""

        resultString += str(self.rolls[self.letters.index(self.STRSbx.get())]) + "|"
        resultString += str(self.rolls[self.letters.index(self.DEXSbx.get())]) + "|"
        resultString += str(self.rolls[self.letters.index(self.CONSbx.get())]) + "|"
        resultString += str(self.rolls[self.letters.index(self.INTSbx.get())]) + "|"
        resultString += str(self.rolls[self.letters.index(self.WISSbx.get())]) + "|"
        resultString += str(self.rolls[self.letters.index(self.CHASbx.get())]) + "\n"
        resultString += str((self.rolls[self.letters.index(self.STRSbx.get())] - 10) // 2) + "|"
        resultString += str((self.rolls[self.letters.index(self.DEXSbx.get())] - 10) // 2) + "|"
        resultString += str((self.rolls[self.letters.index(self.CONSbx.get())] - 10) // 2) + "|"
        resultString += str((self.rolls[self.letters.index(self.INTSbx.get())] - 10) // 2) + "|"
        resultString += str((self.rolls[self.letters.index(self.WISSbx.get())] - 10) // 2) + "|"
        resultString += str((self.rolls[self.letters.index(self.CHASbx.get())] - 10) // 2)

        self.result = resultString
    def rollStats(self):
        tempStats = [0, 0, 0, 0, 0, 0]
        tempRolls = []
        tempStr = ""

        for i in range(len(tempStats)):
            for j in range(4):
                tempRolls.append(rnd.randint(1,6))

            tempRolls.remove(min(tempRolls))

            tempStats[i] = sum(tempRolls)

            tempRolls = []

        for i in range(len(tempStats)):
            self.rolls[i] = tempStats[i]
            tempStr += self.letters[i] + ":" + str(tempStats[i])
            if i < 5:
                tempStr += ", "

        self.rollsVar.set(tempStr)
        self.rolled = True

base = tk.Tk()

ftSmall = tkf.Font(family = "Consolas", size = 8)
ftNormal = tkf.Font(family = "Consolas", size = 10)

diceRollStatsRoot(base)