Wrote very short program to demonstrate this:

import lirc
import time
sockid = lirc.init("python3", ".lircrc". blocking=False)
while True:
    try:
        button = lirc.nextcode()
        print("Looped!")
        if len(button) == 0: continue
        print(button[0])
        time.sleep(1)
    except KeyboardInterrupt:
        lirc.deinit()
        break

This should print "Looped!" every second, and also print the button pressed otherwise. But the program stops (is blocked) at the nextcode() line until a button is pressed. It then passes on the button, and a handful of zero length returns, then goes back to blocking.I've also tried with the separate "set_blocking" line. I can see in the code where it is supposed to set the O_NONBLOCK flag, so maybe it's a bug in LIRC? I'm really new to python, so if I'm misunderstanding something, just let me know please.