Python Tkinter Label Delay

Question

This maybe a silly question to ask. I have a label in Tkinter GUI and i want it to be updated through time.

Example:

Msglabel=Tkinter.Label(... text="")

Msglabel.Cofigure(text=" EXAMPLE!")

Wait(5sec)

Msglabel.Configure(text=" NEW EXAMPLE!")

I've read about the after() method but im looking for something like Wait.

Answer 1

You'll need to hand over control to Tkinter during your wait period since Tkinter updates the UI in a single threaded loop.

Sleeping between the configure calls will hang the UI.

As you mentioned, after is the method you want. Try something like this:

try:
    import Tkinter as tkinter  # Python 2
except ImportError:
    import tkinter  # Python 3
import itertools


class MyApplication(object):
    def __init__(self):
        # Create and pack widgets
        self.root = tkinter.Tk()
        self.label = tkinter.Label(self.root)
        self.button = tkinter.Button(self.root)
        self.label.pack(expand=True)
        self.button.pack()

        self.label['text'] = 'Initial'
        self.button['text'] = 'Update Label'
        self.button['command'] = self.wait_update_label

        # Configure label values
        self.label_values = itertools.cycle(['Hello', 'World'])

    def launch(self):
        self.root.mainloop()

    def wait_update_label(self):
        def update_label():
            value = next(self.label_values)
            self.label['text'] = value

        update_period_in_ms = 1500
        self.root.after(update_period_in_ms, update_label)
        self.label['text'] = 'Waiting...'


if __name__ == '__main__':
    app = MyApplication()
    app.launch()