import threading
import time
from msvcrt import getch

class myThread(threading.Thread):
    def __init__(self,name,switch):
        threading.Thread.__init__(self)
        self.switch = switch
        self.name = name

    def run(self):
        while self.switch == True:
            print('thread running, threads:', threading.enumerate())
            time.sleep(1)

while True:
       key = getch()
       if key == b' ' and 'work' not in str(threading.enumerate()) :
           print('switching on, threads:',threading.active_count())
           thread = myThread('work', True)
           thread.start()

       elif  key == b' ' and 'work' in str(threading.enumerate()):
           thread.switch = False
           thread.join()
           print('swithed off, threads:', threading.enumerate())