How to get a working Progress Bar in python using multi-process or multi-threaded clients?

Question

That's the basic idea.

I couldn't understand them while reading about all this in python's documentation. There's simply too much of it to understand it.

Could someone explain me how to get a working progress bar with a multi-threaded(or multi-process) client?

Or is there any other way to "update" progress bar without locking program's GUI?

Also I did read something about "I/O" errors when these types of clients try to access a file at the same time & X-server errors when an application doesn't call multi-thread libs correctly. How do I avoid 'em?

This time I didn't write code, I don't want to end with a zombie-process or something like that (And then force PC to shutdown, I would hate to corrupt precious data...). I need to understand what am I doing first!

Hagiographer

Hi, I recently acheived something similar (I think) using Tkinter, ttk and the threading module.... I had a moving indeterminate progress bar within my GUI window whilst I ran a function to query a databse through the threading module. The GUI does not lock. Does this sound comparable to your question? – Istic

It sounds similar, but you're using Tkinter, while I'm trying to use PyGobject & Glade, however, it looks useful. Could you show me how to do it? Maybe some piece of code or something? – Hagiographer

Answer 1

Something like the below might get you started? - Ive tried to annotate as much as possible to explain the process.

from Tkinter import *
from Queue import Queue
import ttk, threading
import time

queue = Queue()
root = Tk()

# Function to do 'stuff' and place object in queue for later #
def foo():
    # sleep to demonstrate thread doing work #
    time.sleep(5)
    obj = [x for x in range(0,10)]
    queue.put(obj)

# Create thread object, targeting function to do 'stuff' #
thread1 = threading.Thread(target=foo, args=())

# Function to check state of thread1 and to update progressbar #
def progress(thread, queue):
    # starts thread #
    thread.start()

    # defines indeterminate progress bar (used while thread is alive) #
    pb1 = ttk.Progressbar(root, orient='horizontal', mode='indeterminate')

    # defines determinate progress bar (used when thread is dead) #
    pb2 = ttk.Progressbar(root, orient='horizontal', mode='determinate')
    pb2['value'] = 100

    # places and starts progress bar #
    pb1.pack()
    pb1.start()

    # checks whether thread is alive #
    while thread.is_alive():
        root.update()
        pass

    # once thread is no longer active, remove pb1 and place the '100%' progress bar #
    pb1.destroy()
    pb2.pack()

    # retrieves object from queue #
    work = queue.get()
    return work

work = progress(thread1, queue)
root.mainloop()

Hope this helps. Let me know what you think!

Istic

Yay! Finally some kind of help! Thanks. I've been busy lately doing some misc stuff. In fact, this is the first time I open SO in 3 days. Thanks, I'll try to modify your anwer to fit my proyect. THANKS! (You'ŕe the first one to answer SOMETHING (Not comment) in one of my threads) – Hagiographer

Happy to help! :) Mark as best answer and upvote? :D – Istic

I'm still tryting to do somethin' with this code. Don't worry. If I manage to achieve my purpose, I'll do it – Hagiographer

Nope :c Still trying by my own. – Hagiographer

This example deserves some upvote love. Good guidance to tune for other use-cases. – Hindquarter