How to Schedule Updates (F/E, to Update a Clock) in Tkinter

How can I schedule updates (f/e, to update a clock) in tkinter?

Tkinter root windows have a method called after which can be used to schedule a function to be called after a given period of time. If that function itself calls after you've set up an automatically recurring event.

Here is a working example:

# for python 3.x use 'tkinter' rather than 'Tkinter'
import Tkinter as tk
import time

class App():
    def __init__(self):
        self.root = tk.Tk()
        self.label = tk.Label(text="")
        self.label.pack()
        self.update_clock()
        self.root.mainloop()

    def update_clock(self):
        now = time.strftime("%H:%M:%S")
        self.label.configure(text=now)
        self.root.after(1000, self.update_clock)

app=App()

Bear in mind that after doesn't guarantee the function will run exactly on time. It only schedules the job to be run after a given amount of time. It the app is busy there may be a delay before it is called since Tkinter is single-threaded. The delay is typically measured in microseconds.

Making a Tkinter countdown timer update actively

I modified this How to create a timer using tkinter? to do basically what you want

# for python 3.x use 'tkinter' rather than 'Tkinter'
import Tkinter as tk
import datetime
import math
MINUTE = 60
HOUR = 60*MINUTE
class App():
    def __init__(self):
        self.root = tk.Tk()
        self.done_time=datetime.datetime.now() + datetime.timedelta(seconds=HOUR/2) # half hour
        self.label = tk.Label(text="")
        self.label.pack()
        self.update_clock()
        self.root.mainloop()

    def update_clock(self):
        elapsed = self.done_time - datetime.datetime.now()
        h,m,s,fractional_s = elapsed.seconds/3600,elapsed.seconds/60,elapsed.seconds%60
        fractional_seconds = math.floor(elapsed.microseconds/1000000.0*100)
        self.label.configure(text="%02d:%02d:%02d.%02d"%(h,m,s))
        self.root.after(1000, self.update_clock)

app=App()

(I put fractional_seconds just in case you needed them ...)

How can I schedule updates (f/e, to update a clock) in tkinter?

Tkinter root windows have a method called after which can be used to schedule a function to be called after a given period of time. If that function itself calls after you've set up an automatically recurring event.

Here is a working example:

# for python 3.x use 'tkinter' rather than 'Tkinter'
import Tkinter as tk
import time

class App():
    def __init__(self):
        self.root = tk.Tk()
        self.label = tk.Label(text="")
        self.label.pack()
        self.update_clock()
        self.root.mainloop()

    def update_clock(self):
        now = time.strftime("%H:%M:%S")
        self.label.configure(text=now)
        self.root.after(1000, self.update_clock)

app=App()

Bear in mind that after doesn't guarantee the function will run exactly on time. It only schedules the job to be run after a given amount of time. It the app is busy there may be a delay before it is called since Tkinter is single-threaded. The delay is typically measured in microseconds.

How can I schedule updates (f/e, to update a clock) in tkinter?

Tkinter root windows have a method called after which can be used to schedule a function to be called after a given period of time. If that function itself calls after you've set up an automatically recurring event.

Here is a working example:

# for python 3.x use 'tkinter' rather than 'Tkinter'
import Tkinter as tk
import time

class App():
    def __init__(self):
        self.root = tk.Tk()
        self.label = tk.Label(text="")
        self.label.pack()
        self.update_clock()
        self.root.mainloop()

    def update_clock(self):
        now = time.strftime("%H:%M:%S")
        self.label.configure(text=now)
        self.root.after(1000, self.update_clock)

app=App()

Bear in mind that after doesn't guarantee the function will run exactly on time. It only schedules the job to be run after a given amount of time. It the app is busy there may be a delay before it is called since Tkinter is single-threaded. The delay is typically measured in microseconds.

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