Tkinter window not opening when importing time

Question

I am running a simple clock program that I made and while editing it I had a problem. The clock worked on its own with a print statement and the tinter window also worked on its own but together it doesn't work. I recreated it with importing the tkinter library first then later added the time import and I stopped working. What can I do? Here is my code. (I am running python v3.6.5)`

import time
from tkinter import*
hours = int(input("what hour is it?"))
minutes = int(input("what minute is it?"))
seconds = int(input("what second is it?"))
window = Tk()
texthours = Text(window, width=1, height=1)
textminutes = Text(window, width=1, height=1)
textseconds = Text(window, width=1, height=1)
textseconds.pack()
textminutes.pack()
texthours.pack()
while 1==2-1:
    time.sleep(1)
    texthours.delete(0.0, END)
    textminutes.delete(0.0, END)
    textseconds.delete(0.0, END)
    texthours.insert(END, hours)
    textminutes.insert(END, minutes)
    textseconds.insert(END, seconds)
    seconds = seconds + 1
    if seconds == 60:
        minutes = minutes + 1
        seconds = 0
    if minutes == 60:
        hours = hours + 1
        minutes = 0
    if hours == 24:
        hours = 0

`

Answer 1

A GUI program normally uses an event-driven execution model. That means you build the GUI, and it sits in a loop waiting for events to happen, which it responds to. But in your program there's an infinite while loop, so the GUI doesn't get a chance to do anything.

There are better ways to do this, but here's a repaired version of your code with minimal changes.

It's not a good idea to use time.sleep in a GUI program because that puts everything to sleep, so the GUI can't respond to events. In Tkinter, you can call a function periodically using the .after method.

import tkinter as tk

hours = int(input("what hour is it? "))
minutes = int(input("what minute is it? "))
seconds = int(input("what second is it? "))

window = tk.Tk()

texthours = tk.Text(window, width=2, height=1)
textminutes = tk.Text(window, width=2, height=1)
textseconds = tk.Text(window, width=2, height=1)

texthours.pack(side=tk.LEFT)
textminutes.pack(side=tk.LEFT)
textseconds.pack(side=tk.LEFT)

def show_time():
    global hours, minutes, seconds

    texthours.delete(0.0, tk.END)
    textminutes.delete(0.0, tk.END)
    textseconds.delete(0.0, tk.END)
    texthours.insert(tk.END, hours)
    textminutes.insert(tk.END, minutes)
    textseconds.insert(tk.END, seconds)
    seconds = seconds + 1
    if seconds == 60:
        minutes = minutes + 1
        seconds = 0
    if minutes == 60:
        hours = hours + 1
        minutes = 0
    if hours == 24:
        hours = 0
    window.after(1000, show_time)

window.after(1000, show_time)
window.mainloop()

---

Here's a slightly better version, which wraps everything up into a class, so we don't need to use global. This involves a little more typing, but it makes things more manageable, especially in large complex GUIs.

import tkinter as tk

class Clock:
    def __init__(self):
        self.hours = int(input("what hour is it? "))
        self.minutes = int(input("what minute is it? "))
        self.seconds = int(input("what second is it? "))

        self.window = tk.Tk()

        self.texthours = tk.Text(self.window, width=2, height=1)
        self.textminutes = tk.Text(self.window, width=2, height=1)
        self.textseconds = tk.Text(self.window, width=2, height=1)

        self.texthours.pack(side=tk.LEFT)
        self.textminutes.pack(side=tk.LEFT)
        self.textseconds.pack(side=tk.LEFT)

        self.window.after(1000, self.show_time)
        self.window.mainloop()

    def show_time(self):
        self.texthours.delete(0.0, tk.END)
        self.textminutes.delete(0.0, tk.END)
        self.textseconds.delete(0.0, tk.END)
        self.texthours.insert(tk.END, self.hours)
        self.textminutes.insert(tk.END, self.minutes)
        self.textseconds.insert(tk.END, self.seconds)
        self.seconds += 1
        if self.seconds == 60:
            self.minutes += 1
            self.seconds = 0
        if self.minutes == 60:
            self.hours += 1
            self.minutes = 0
        if self.hours == 24:
            self.hours = 0
        self.window.after(1000, self.show_time)

Clock()