How do I run a function every four minutes since a specific epoch?

Question

My main function calls a number of subroutines in a while True: loop.

I want to add another function g() that only runs once every four minutes. Function g() should only run at 4 minutes, 8 minutes, 12 minutes, etc

I know I can check if a single amount of time has passed with if epoch >= x

But how do I run only g() every four minutes?

def main():
    epoch = time.time()
    count = 0 
    while True:        
        count = count + 1        
        if a() == 1:
            b()
            c()
            d()
            if count % 20:
                e()
            else:
                f()
            e()
            if epoch >= 240:
                g()
            

Edit; I can't run this as a separate thread as the answer in the duplicate suggested.

Answer 1

Create a new variable to store the next time the function should run:

import time
def main():
    epoch = time.time()
    count = 0
    next_g = 0
    while True:        
        count = count + 1        
        if a() == 1:
            b()
            c()
            d()
            if count % 20:
                e()
            else:
                f()
            e()
            if (epoch := time.time()) >= next_g:
                g()
                next_g = epoch + 240