Python Loops...

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April 3rd, 2004, 09:26 AM

Johnny5ive

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Join Date: Mar 2004

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Python Loops...

Hello all..

I'm writing a script for xChat with Python. Currently, there is a loop I am creating that needs to happen every X seconds, and for the commands in that loop to happen in between. Not only that, but the other parts of the script have to also respond as triggered by the text in the channel. Here is what I have for the loop:

(assuming the variables are set correctly, listTime is set @ 60, and fileTime is set @ 120)

Code:

def mainLoop():
    global listTime
    global fileTime
    global xPyGetPower
    listTimer = listTime
    fileTimer = fileTime
    while xPyGetPower == 'on':
        if requestLists == 'on':
            if listAvailable:
                if listTimer == 1:
                    request_list()
                    listTimer = listTime
                else:
                    listTimer = listTimer-1
        if requestFiles == 'on':
            if fileAvailable:
                if fileTimer == 1:
                    request_file()
                    fileTimer = fileTime
                else:
                    fileTimer = fileTimer-1
        sleep(2)

Here's the problem. I fire the baby up, and it just sits there. Oh it loads the script, but I can't do anything else, and the rest of the script doesn't respond.

So how do I create a timed loop (every 2 seconds) that allows for the rest of the script to run at the same time (i'm assuming this is multithreading?) and doesn't lock up the program?!?

Any help would be appreciated!

Last edited by Johnny5ive : April 3rd, 2004 at 09:28 AM.

April 3rd, 2004, 10:48 AM

DevCoach

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Posts: 1,585

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Yes, you will need to use threads to do what you want. This can be a scary, complex topic but the basics are quite simple.

Instead of calling your mainloop function directly you can run it in a separate thread like this:

Code:

import threading

thread = threading.Thread(target=mainloop)
thread.start()
#do the rest of your script...

(I suggest renaming the 'mainloop' function, since it is no longer part of the main thread)

The thread will end when the function terminates.

The main problem to watch out for when using threads is having two threads access the same objects at the same time. There are various ways round this, which are documented in the threading module.

A quick search on google found this tutorial on threading in Python at http://heather.cs.ucdavis.edu/~matl...n/PyThreads.pdf.

Hope this helps

Dave - The Developers' Coach