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Python: Alternating functions every x minutes

Say if I have four functions as below:

def foo():
    subprocess.Popen('start /B someprogramA.exe', shell=True)

def bar():
    subprocess.Popen('start /B someprogramB.exe', shell=True)

def foo_kill():
    subprocess.Popen('taskkill /IM someprogramA.exe')

def bar_kill():
    subprocess.Popen('taskkill /IM someprogramB.exe')

How can I alternate foo and bar functions to run every, say 30 minutes? Meaning: 1st 30mins - run foo, 2nd 30mins - run bar, 3rd 30mins - run foo, and so on. Each new run should 'kill' the previous thread/func.

I have a countdown timer threads, but not sure how to 'alternate' the functions.

class Timer(threading.Thread):
    def __init__(self, minutes):
        self.runTime = minutes
        threading.Thread.__init__(self)


class CountDownTimer(Timer):
    def run(self):
        counter = self.runTime
        for sec in range(self.runTime):
            #do something           
            time.sleep(60) #editted from 1800 to 60 - sleeps for a minute
            counter -= 1

timeout=30
c=CountDownTimer(timeout)
c.start()

EDIT: My solution with Nicholas Knight's inputs...

import threading
import subprocess
import time

timeout=2 #alternate delay gap in minutes

def foo():
    subprocess.Popen('start /B notepad.exe', shell=True)

def bar():
    subprocess.Popen('start /B calc.exe', shell=True)

def foo_kill():
    subprocess.Popen('taskkill /IM notepad.exe')

def bar_kill():
    subprocess.Popen('taskkill /IM calc.exe')


class Alternator(threading.Thread):
    def __init__(self, timeout):
        self.delay_mins = timeout 
        self.functions = [(foo, foo_kill), (bar, bar_kill)]
        threading.Thread.__init__(self)

    def run(self):
        while True:
            for f, kf in self.functions:
                f()
                time.sleep(self.delay_mins*60)
                kf()

a=Alternator(timeout)
a.start()

Works fine.

like image 621
siva Avatar asked May 23 '11 17:05

siva


3 Answers

Remember that functions are first-class objects in Python. That means you can store them in variables and containers! One way to do it would be:

funcs = [(foo, foo_kill), (bar, bar_kill)]

def run(self):
    counter = self.runTime
    for sec in range(self.runTime):
        runner, killer = funcs[counter % 2]    # the index alternates between 0 and 1
        runner()    # do something
        time.sleep(1800)
        killer()    # kill something
        counter -= 1
like image 113
Santa Avatar answered Nov 14 '22 12:11

Santa


You're overcomplicating this.

while True:
    foo()
    time.sleep(1800)
    foo_kill()
    bar()
    time.sleep(1800)
    bar_kill()

Or if you want to easily add more functions later:

functions = [(foo, foo_kill), (bar, bar_kill), ] # Just append more as needed
while True:
    for f, kf in functions:
        f()
        time.sleep(1800)
        kf()
like image 22
Nicholas Knight Avatar answered Nov 14 '22 13:11

Nicholas Knight


Use a variable to record which function you ran last time. When the timer fires, run the other function and update the variable.

like image 22
LaC Avatar answered Nov 14 '22 12:11

LaC