Use start and stop function with same button in Tkinter

Question

With the help of the command button, I am able to disconnect the frame in Tkinter. But is there any way which helps to use the same button to start also?

import tkinter as tk
counter = 0
def counter_label(label):
  def count():
    global counter
    counter+=1
    label.config(text=counter)
    label.after(1000, count)
  count()


root = tk.Tk()
root.title("Counting Seconds")
label = tk.Label(root, fg="green")
label.pack()
counter_label(label)
button = tk.Button(root, text='Stop', width=25, command=root.destroy)
button.pack()
root.mainloop()

Suggestions will be grateful

Answer 1

You could simple use an if/else statement to check if the buttons text is Start or Stop then change a Boolean variable that controls the counter while also update the text on the button.

import tkinter as tk

counter = 0
active_counter = False


def count():
    if active_counter:
        global counter
        counter += 1
        label.config(text=counter)
        label.after(1000, count)


def start_stop():
    global active_counter
    if button['text'] == 'Start':
        active_counter = True
        count()
        button.config(text="Stop")
    else:
        active_counter = False
        button.config(text="Start")


root = tk.Tk()
root.title("Counting Seconds")
label = tk.Label(root, fg="green")
label.pack()
button = tk.Button(root, text='Start', width=25, command=start_stop)
button.pack()
root.mainloop()

Here is an OOP example as well:

import tkinter as tk


class App(tk.Tk):
    def __init__(self):
        super().__init__()
        self.title("Counting Seconds")
        self.counter = 0
        self.active_counter = False
        self.label = tk.Label(self, fg="green")
        self.label.pack()
        self.button = tk.Button(self, text='Start', width=25, command=self.start_stop)
        self.button.pack()

    def count(self):
        if self.active_counter:
            self.counter += 1
            self.label.config(text=self.counter)
            self.label.after(1000, self.count)

    def start_stop(self):
        if self.button['text'] == 'Start':
            self.active_counter = True
            self.count()
            self.button.config(text="Stop")
        else:
            self.active_counter = False
            self.button.config(text="Start")


if __name__ == "__main__":
    App().mainloop()

Answer 2

This code is overly complicated (my answer), I suggest improving it. But it shows how one could use the same button for both start and stop as well as keeping most of your code.

import tkinter as tk

def counter_label(label):
    a = 0
    label.config(text=str(a))
    def count():
        nonlocal a
        label.config(text=str(a))
        a += 1
        label.after(1000, count)
    return count

def start_stop(root, btn_text, counter):
    first = True
    def call():
        nonlocal first
        if first:
            counter()
            first = False
            btn_text.set('Stop')
        else:
            root.destroy()
    return call

root = tk.Tk()
root.title("Counting Seconds")
label = tk.Label(root, fg="green")
label.pack()
counter = counter_label(label)
btn_text = tk.StringVar()
button = tk.Button(root, textvariable=btn_text, width=25, command=start_stop(root, btn_text, counter))
btn_text.set('Start')
button.pack()
root.mainloop()