Math Quiz test file | Python Fiddle

from Tkinter import *
import time
import tkMessageBox
import random

def Questions():    
    number1 = random.randrange(1,25,1)
    number2 = random.randrange(1,50,2)
    answer = number1 + number2
    prompt = ("Add " + str(number1) + " and " + str(number2))
    label1 = Label(root, text=prompt, width=len(prompt), bg='yellow')
    label1.pack()
    return answer

def start():
    global count_flag 
    Questions()
    count_flag = True
    count = 0.0
    while True:
        if count_flag == False:
            break
        # put the count value into the label
        label['text'] = str(count)
        # wait for 0.1 seconds
        time.sleep(0.1)
        # needed with time.sleep()
        root.update()
        # increase count
        count += 0.1

def Submit(answer, entryWidget):
     """ Display the Entry text value. """
     global count_flag

count_flag = False
     print answer

if entryWidget.get().strip() == "":
         tkMessageBox.showerror("Tkinter Entry Widget", "Please enter a number.")

if int(answer) != entryWidget.get().strip():
         tkMessageBox.showinfo("Answer", "INCORRECT!")
     else:
         tkMessageBox.showinfo("Answer", "CORRECT!")

# create a Tkinter window
root = Tk()

root.title("Math Quiz")
root["padx"] = 40
root["pady"] = 20

# Create a text frame to hold the text Label and the Entry widget
textFrame = Frame(root)

#Create a Label in textFrame
entryLabel = Label(textFrame)
entryLabel["text"] = "Answer:"
entryLabel.pack(side=LEFT)

# Create an Entry Widget in textFrame
entryWidget = Entry(textFrame)
entryWidget["width"] = 50
entryWidget.pack(side=LEFT)

textFrame.pack()

#directions     
directions = ('Click start to begin. You will be asked a series of questions like the one below.')
instructions = Label(root, text=directions, width=len(directions), bg='orange')
instructions.pack()

# this will be a global flag
count_flag = True

answer = Questions()

Sub = lambda: Submit(answer, entryWidget)

# create needed widgets
label = Label(root, text='0.0')
btn_submit = Button(root, text="Submit", command = Sub)
btn_start = Button(root, text="Start", command = start)
btn_submit.pack()
btn_start.pack()
label.pack()

# start the event loop
root.mainloop()

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