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pythontkintertimercrash

Tkinter code for a Timer is crashing the app (python)


I am creating a timer for my quiz app and I decided to try it out first in a separate program, however when I run the following code and press the 'start timer' button the app simply stops responding and I am forced to close it through the task manager

from tkinter import *
import time

root=Tk()
root.geometry('{}x{}'.format(300,200))

lb=Label(root,text='')
lb.pack()

def func(h,m,s):

    lb.config(text=str(h)+':'+str(m)+':'+str(s))
    time.sleep(1)
    s+=1

    func(h,m,s)
    if s==59:
        m=1
        s=0

bt=Button(root,text='start timer',command=lambda:func(0,0,0))
bt.pack()

root.mainloop()

Solution

  • You need to use root.after instead of time.sleep. Here's another answer about making a timer. This is what it looks like applied to your code:

    from tkinter import *
    import time
    
    root=Tk()
    root.geometry('{}x{}'.format(300,200))
    
    lb=Label(root,text='')
    lb.pack()
    
    def func(h,m,s):
    
        lb.config(text=str(h)+':'+str(m)+':'+str(s))
        s+=1
        if s==59:
            m=1
            s=0
        root.after(1000, lambda: func(h,m,s))
    
    bt=Button(root,text='start timer',command=lambda:func(0,0,0))
    bt.pack()
    
    root.mainloop()