why two balls?

check this blend (2.49b)

press space to send a message “now”
the two spawner activates when “now” message coming
but the left makes TWO balls (it uses python script to activate the actuator)

Notice that it adds a ball when you press and release the key, that`s why it adds 2 objects

this one should fix it
rename your message sensor from “sensor1” to “now”

c = g.getCurrentController()
now = c.sensors["now"]

if now.positive:
    print('..............new ball!!!...........')

hm… thank you, interesting… with your code it works correct

but the right does not make two balls, why? it gets same message as the left

i am not really sure, it seems that sensor sends an impulse to python controller whenever sensor value changes.

I can’t download your file from my current location.
I assume you activate the right one with an AND actuator?

In that case keep in mind that the controllers

  • activate the connected actuators when they calculate True out of the input (from the sensors).
  • deactivate the connected actuators when they calculate False out of the input (from the sensors).

The Python controllers must explicit perform this behaviour by the script.
Your script was activating the actuators in both cases.

You always have to make a choice out of

  • activate
  • deactivate
  • leave an actuator’s state as it is
    for each single connected actuator.

I hope it helps