alarm_clock_class.py

from tkinter import *
import time
import os

class GUI:
    def __init__(self):
        self.quitting = False
        self.alarm_state = False
        self.win = Tk()
        self.win.title("Clock")
        self.win.protocol("WM_DELETE_WINDOW", self.quitter) ## runs the function when the X button is pressed.

    def quitter(self): # function controls how the application should close
        self.quitting = True

    def button(self): #Triggers the application to start checking the alarm to see if it has elapsed
        self.alarm_state = True

    def check_alarm(self):
        if self.alarm.get()==time.strftime('%H:%M:%S'):
            print("Times Up!")
            self.alarm_state = False

    def run(self):
        timer = Label(self.win,font=('times', 28, 'bold'), background='blue', foreground='white') ##renamed this to be easier to read
        timer.pack(fill=BOTH, expand=1)
        self.alarm=Entry(self.win)
        self.alarm.pack()
        bt=Button(self.win, text='Set alarm', command=self.button).pack()
        while not self.quitting:
            self.win.update()
            self.win.update_idletasks()
            timer["text"]  = time.strftime('%H:%M:%S')
            if self.alarm_state:
                self.check_alarm()

if __name__ == "__main__":
    app= GUI() ##creates the app as an object
    try:
        app.run() ##runs the application
    except KeyboardInterrupt:
        app.quitter() ##safly quits the application if ctrl+c is pressed
    except:
        raise ##displays any other errors