Progress bar class implemented in Python.

progress_bar.py

from __future__ import with_statement

import threading
import sys

# Implementation of Ticker class
class Ticker(threading.Thread):
    def __init__(self, msg):
        threading.Thread.__init__(self)
        self.msg = msg
        self.event = threading.Event()
    def __enter__(self):
        self.start()
    def __exit__(self, ex_type, ex_value, ex_traceback):
        self.event.set()
        self.join()
    def run(self):
        sys.stdout.write(self.msg)
        while not self.event.isSet():
            sys.stdout.write(".")
            sys.stdout.flush()
            self.event.wait(1)

# Here's how we use it...
if __name__ == '__main__':
    import time
    with Ticker("A test"):
        time.sleep(10)
    with Ticker("Second test"):
        time.sleep(5)
        raise Exception("Done!")