Tkinter ignores root.after delay-CodePudding

Tkinter ignores root.after The countdown animation plays but it ignores the delay and does everything that's after root.after before the countdown is over

All tests suggest that the countdown is happending and the variable is changing, it just skips the delay

    global TimeLable, ErrorLabel
    #destoryes error labels and the countdown timer
    try:
        for child in root.winfo_children():
            if child == TimeLable or child == ErrorLabel:
                child.destroy()
    except NameError:
        pass
    #needed for fail-safe 1
    mouse = MouseController()

    countdown_value = 5
    counter = tk.StringVar()
    counter.set(countdown_value)
    TimeLable = tk.Label(frame, textvariable=counter, padx=10, pady=5, bg=Modes[mode.get()][3]['background'], fg=Modes[mode.get()][2]['text'])
    TimeLable.pack()

    #coundown
    for countdown in range(1, countdown_value):
        root.after(1000 * countdown, counter.set, countdown_value - countdown)
    x = 100
    y = 100
    try:
        with open(PreferencesStorage['FilePath'], 'r') as SpamText: 
            while PreferencesStorage['loop']:
                for word in SpamText:
                    #fail safe 1
                    if x < 21 and y < 21:
                        break
                    TempX, TempY = mouse.position
                    x = int(TempX)
                    y = int(TempY)
                    #fail-safe 2
                    if keyboard.is_pressed('ctrl d'):
                        break
                    keyboard.write(word)
                    print(word)
                #return to begining when at end, thats why its outside of the loop
                SpamText.seek(0)
            for word in SpamText:
                keyboard.write(word)
    except FileNotFoundError:
        NoFile = tk.Label(frame, text = 'Please Select A File', padx=10, pady=5, fg=Modes[mode.get()][2]['text'], bg=Modes[mode.get()][3]['background'])
        NoFile.pack()```

CodePudding user response：

root.after does not cause a delay. What that says is "please have the main loop call this function later". Your code is going to queue up 5 timer callback requests very quickly, and then continue on. The callbacks will happen later.

When you're coding for a GUI, you have to start thinking about event-driven programming. When you create widgets or call "pack", NOTHING HAPPENS. All that does is queue up a message to be handled later. At some future point, when the mainloop is able to execute, your messages will be popped off and processed. Only then will your visible screen change. That requires a change in the way you program things. You set up your screen, start the mainloop, and then wait for events. Your event callbacks change the state and return, and Tk in the background will update the screen.