Why does this hang the system up

[Able98]

Does this help?

class PasswordFoundException (Exception):
    pass

def attempt(w, pw):
    
    # sys.stdout.write("\r")

    # sys.stdout.write("\rAttempt #%d: %s" % (counter.value, pw)) #prints simple progress with # in list that is tested and the pw string
    sys.stdout.write("Attempt #%d: %s\n" % (counter.value, pw)) #prints simple progress with # in list that is tested and the pw string

    sys.stdout.flush()
    #print(counter.value)
    counter.increment()

    if len(pw) < 10:
        return ""
    
    try:
        o = decode_keystore_json(w,pw)
        print("Password is: ", pw, "   ", o)
        
        raise PasswordFoundException("Password Found")
        
    except ValueError as e:
        # print(e)
        return ""

class Counter(object):
    def __init__(self):
        self.val = multiprocessing.Value('i', 0)

    def increment(self, n=1):
        with self.val.get_lock():
            self.val.value += n

    @property
    def value(self):
        return self.val.value

def __main__():
    global counter
    counter = Counter()
    pwds = []
    pwds = itertools.chain(pwds, generate_all(grammar,''))

    try:
        Parallel(n_jobs=-1)(delayed(attempt)(w, pw) for pw in pwds)

    except Exception as e:
        traceback.print_exc()
        while True:
            sys.stdout.write('\a')
            sys.stdout.flush()

if __name__ == "__main__":
    __main__()