Playing with threads using Python

app-threads.py

import threading, time, random

class Counter (threading.Thread):
    num = 0

    def reset(self):
        self.num = 0

    def run(self):
        while True:
            time.sleep(random.uniform(0.2, 1.5))
            self.math()
            print self.num

class Up (Counter):
    def math(self):
        self.num += 1

class Down (Counter):
    def math(self):
        self.num -= 1

up = Up()
up.daemon = True
up.start()

down = Down()
down.daemon = True
down.start()

while True:
    key = raw_input()
    up.reset()
    down.reset()