How to fully close tkinter window that has matplotlib figures using x button?

Question

I have made a python program that creates a tkinter window, with multiple tabs. Each tab shows a different matplotlib figure.

My problem is that when I press the x button in the top right corner to close the window, the window appears to close but I cannot enter a new command into the terminal, indicating that the program is still running. I have to close the terminal to fully stop the program. How do I fix this?

This is a short version of my code:

import numpy as np 
import h5py as h5 
import pandas as pd 
import matplotlib.pyplot as plt
import matplotlib.colors as colors
import tkinter as tk
from tkinter import ttk
from matplotlib.backends.backend_tkagg import (FigureCanvasTkAgg, NavigationToolbar2Tk) 

window = tk.Tk()
window.title("Plotting data in the hdf5 file")
mytabs = ttk.Notebook(window)

tab1 = ttk.Frame(mytabs)
tab2 = ttk.Frame(mytabs)
tab3 = ttk.Frame(mytabs)
tab4 = ttk.Frame(mytabs)

mytabs.add(tab1, text = "Velocity")
mytabs.add(tab2, text = "Momentum Flux")
mytabs.add(tab3, text = "Pressure and forcing")
mytabs.add(tab4, text = "Diagram")
mytabs.pack(expand = 1, fill ="both")


## code to read some data here 

## code to make 4 different figures here 
## fig, ax = plt.subplots(2,2, figsize = (12,12))
## ... etc.


def plot(fig,tab): 
    canvas = FigureCanvasTkAgg(fig, master = tab)   
    canvas.draw() 
    canvas.get_tk_widget().pack()  
    toolbar = NavigationToolbar2Tk(canvas, tab) 
    toolbar.update() 
    canvas.get_tk_widget().pack() 

plot(fig,tab1)
plot(fig2,tab2)
plot(fig3,tab3)
plot(fig4,tab4)

window.mainloop()

I am on Ubuntu 22.04.4 LTS if it matters.

Answer 1

def on_closing():
    window.quit()  
    window.destroy()   
                      


window.protocol("WM_DELETE_WINDOW", on_closing)

It's not clear why this is happening, but try this function called it just before you call the main loop ( so at the end, just before the last line)

This function window.quit() basically stops the main loop. window.destroy() makes sure that the window closed. And then just pass it as a protocol for WM_DELETE_WINDOW