How do I change a variable periodically while keeping the rest of my programming running at normal speed?

Question

I'm trying to make a game sort of like cookie-clicker, but the problem I'm having is that I want to change the "money" variable once every second while keeping the rest of the program running at normal speed. (i.e. when you click a button to bring up a menu, it doesn't take a second to refresh.

Answer 1

Make a thread which allows you to simultaneously run tasks:

from threading import *
import time

class CookieThread(Thread):
    def __init__(self, rate):
        self.money = 0
        self.rate = rate
        self.running = False
        super(Thread, self).__init__()

    def start(self):
        self.running = True
        super(Thread, self).start()

    def run(self):
        while self.running:
            self.money += self.rate
            time.sleep(1) # wait a second

Now create a thread and start it:

cookie = CookieThread(10)
cookie.start()

Answer 2

You have two main choices (for Python, or for any language):

• Create a thread (which executes in an infinite loop, and wakes up ever n seconds to do work asynchronously), or

• Create a timer (which asynchronously jumps to your "interrupt handler" every N seconds).

Here is a good threads tutorial:

• http://www.tutorialspoint.com/python/python_multithreading.htm

This is a simple "alarm" handler:

https://docs.python.org/3/library/signal.html

import signal, os

def handler(signum, frame):
    print('Signal handler called with signal', _)

# Set the alarm to fire every second
signal.signal(signal.SIGALRM, handler)
signal.alarm(1)

# ... Do stuff - the alarm will keep firing ...

# Done: clear alarm
signal.alarm(0)