Quick CLI animation context manager

animated.py

import threading
import time
import sys

from itertools import cycle

class Animated():
    def __init__(self, anim="|/-\\"):
        self.anim = anim
        self.run_lock = threading.Lock()
        self.thread = threading.Thread(target=self.loop, name='AnimatedThread')

    def __enter__(self):
        self.start()

    def __exit__(self, *e):
        self.stop()

    def start(self):
        self.thread.start()

    def stop(self):
        self.run_lock.acquire(blocking=True)
        self.thread.join()
        self.run_lock.release()

    def loop(self):
        sys.stdout.write(self.anim[0])
        for a in cycle(self.anim):
            keep_running = self.run_lock.acquire(blocking=False)
            if not keep_running: break
            try: # overengineered since subthread exceptions ruin the program anyways
                sys.stdout.write('\r' + a)
            finally:
                sys.stdout.write('\r')
                self.run_lock.release()
            time.sleep(.2)