Simple Python CLI Spinner

spinner.py

#!/usr/bin/env python
# source: https://gist.github.com/cevaris/79700649f0543584009e
# updated to allow an arbitrary message to be displayed in front of the spinner

import itertools
import sys
import time
import threading


class Spinner(object):
    msg = ''
    spinner_cycle = itertools.cycle(['-', '/', '|', '\\'])

    def __init__(self, msg=None):
        if msg is not None:
            self.msg = msg

        self.stop_running = threading.Event()
        self.spin_thread = threading.Thread(target=self.init_spin)

    def start(self):
        self.spin_thread.start()

    def stop(self):
        self.stop_running.set()
        self.spin_thread.join()
        sys.stdout.write("\n")

    def init_spin(self):
        while not self.stop_running.is_set():
            sys.stdout.write(self.msg)
            sys.stdout.write(next(self.spinner_cycle))
            sys.stdout.flush()
            time.sleep(0.25)
            sys.stdout.write("\b" * (len(self.msg) + 1))

spinner_usage.py

#!/usr/bin/env python

def do_work():
    time.sleep(3)

print 'starting work'    

spinner = Spinner()
spinner.start()

do_work()

spinner.stop()
print 'all done!'