Python join a process without blocking parent

Question

I\'m writing a program that will watch a particular directory for new files containing download URLs. Once a new file is detected, it will create a new process to do the act

Answer 1

You can set up a separate thread which does the joining. Have it listen on a queue into which you push the subprocess handles:

class Joiner(Thread):
    def __init__(self, q):
        self.__q = q
    def run(self):
        while True:
            child = self.__q.get()
            if child == None:
                return
            child.join()

Then, instead of p.join(), do joinq.put(p) and do a joinq.put(None) to signal the thread to stop. Make sure you use a FIFO queue.