tkinter progress bar example with threading

tkinter_progress.py

"""
An examnple of the use of threading to allow simultaneous operations in a
tkinter gui (which is locked to a single thread)
"""

import threading
import tkinter as tk
from tkinter import ttk


class Progress():
    """ threaded progress bar for tkinter gui """
    def __init__(self, parent, row, column, columnspan):
        self.maximum = 100
        self.interval = 10
        self.progressbar = ttk.Progressbar(parent, orient=tk.HORIZONTAL,
                                           mode="indeterminate",
                                           maximum=self.maximum)
        self.progressbar.grid(row=row, column=column,
                              columnspan=columnspan, sticky="we")
        self.thread = threading.Thread()
        self.thread.__init__(target=self.progressbar.start(self.interval),
                             args=())
        self.thread.start()

    def pb_stop(self):
        """ stops the progress bar """
        if not self.thread.isAlive():
            VALUE = self.progressbar["value"]
            self.progressbar.stop()
            self.progressbar["value"] = VALUE

    def pb_start(self):
        """ starts the progress bar """
        if not self.thread.isAlive():
            VALUE = self.progressbar["value"]
            self.progressbar.configure(mode="indeterminate",
                                       maximum=self.maximum,
                                       value=VALUE)
            self.progressbar.start(self.interval)

    def pb_clear(self):
        """ stops the progress bar """
        if not self.thread.isAlive():
            self.progressbar.stop()
            self.progressbar.configure(mode="determinate", value=0)

    def pb_complete(self):
        """ stops the progress bar and fills it """
        if not self.thread.isAlive():
            self.progressbar.stop()
            self.progressbar.configure(mode="determinate",
                                       maximum=self.maximum,
                                       value=self.maximum)

def printmsg():
    """ prints a message in a seperate thread to tkinter """
    print("proof a seperate thread is running")


class AppGUI(tk.Frame):
    """ class to define tkinter GUI"""
    def __init__(self, parent,):
        tk.Frame.__init__(self, master=parent)
        prog_bar = Progress(parent, row=0, column=0, columnspan=2)
        # Button 1
        start_button = ttk.Button(parent, text="start",
                                  command=prog_bar.pb_start)
        start_button.grid(row=1, column=0)
        # Button 2
        stop_button = ttk.Button(parent, text="stop",
                                 command=prog_bar.pb_stop)
        stop_button.grid(row=1, column=1)
        # Button 3
        complete_button = ttk.Button(parent, text="complete",
                                     command=prog_bar.pb_complete)
        complete_button.grid(row=2, column=0)
        # Button 4
        clear_button = ttk.Button(parent, text="clear",
                                  command=prog_bar.pb_clear)
        clear_button.grid(row=2, column=1)
        # Button 5
        test_print_button = ttk.Button(parent, text="thread test",
                                       command=printmsg)
        test_print_button.grid(row=3, column=0, columnspan=2, sticky="we")


ROOT = tk.Tk()
APP = AppGUI(ROOT)
ROOT.mainloop()

This doesn't really work. Creating a simple time.sleep() inside function printmsg: stops the progressbar from moving for the duration of sleep.

First of all this:

self.thread = threading.Thread()
self.thread.__init__(target=self.progressbar.start(self.interval),
                             args=())

is very unpythonic. Also you aren't calling self.progressbar.start in the new thread. You are calling it then setting target to what ever the function returns (probably None). Also why do you have args=() you can just remove it.

Also all event/commands (like command=printmsg) run the the tkinter thread.