Unable to kill / terminate programs if another terminal window opened

Question

I’m running a program on raspberry pi which opens few other python programs for a certain amount of time and then closes them. What is happening:

• if I’m running the main program from e.g. Python 3 IDE or Thonny Python or other IDEs, everything works fine, it opens and closes all programs as expected.
• if I’m running the main program from e.g. Python 3 IDE or Thonny Python or other IDEs, but I have some other terminal window opened (not even running anything, just opened and sitting idle), it will open all the programs, but it’s unable to close them down after.
• if I’m running the main program in terminal window, it will open all the programs, but it is unable to close them down after.

code e.g.

while True:
    proc = subprocess.Popen(['lxterminal', '-e', ' test_aa.py'])
    proc_bb = subprocess.Popen(['lxterminal', '-e', 'test_bb.py'])
    time.sleep(5)
    proc.terminate()
    proc_bb.kill()
    time.sleep(200)

Another example

while True:
    print("opening")
    proc = subprocess.Popen(['lxterminal', '-e', ' test_aa.py'])
    c = proc.pid 
    print(c)
    time.sleep(3)
    os.kill(c, signal.SIGTERM)
    time.sleep(700)

works if no other terminal window opened manually,

To start the programs I also tried different variations of Popen and os.system, they work every time fine.

To kill/terminate I’ve tried: os.system, os.kill(pid, signal.SIGTERM), os.kill(pid, signal.SIGINT) etc. kill with -9 PID, subprocess.Popen and then kill() or terminate()

UPDATE 1

As per my question above, I think I can partially answer it, but at the same time this will raise more questions.

Taking under consideration this code:

while True:
    print("opening")
    proc = subprocess.Popen(['lxterminal', '-e', ' test_aa.py'])
    c = proc.pid 
    print(c)
    time.sleep(3)
    os.kill(c, signal.SIGTERM)
    time.sleep(700)

using

  ps aux 

I found that

   ['lxterminal'] 

And

   ['test_aa.py']

Are running with different pid numbers. So

    c = proc.pid 

is giving me pid for ['test_aa.py'] and this probably could explain why I can’t terminate ['lxterminal']

Am I correct in saying that?

What would be other options to start a python program in another terminal window, but to make sure they have same pid numbers?

UPDATE 2

I'm running the new terminal window under one pid number – so that’s sorted. I’m also using code to make sure there is no zombie process running:

stdout, stderr = proc.communicate()
proc.wait()

and it does work, no zombie process running after.

But unfortunately same story again, if I open some terminal window and run my program it won’t terminate terminal started by my program. I tried on two different raspberry pi. Same thing.

Why if I have another terminal window opened, it suddenly fails to close my programs?

FINAL UPDATE

I’m partially answering my own question

I still don’t understand why if I had some terminal window opened my program wasn't terminating other programs, but I found a way around it. Instead of

 lxterminal, 

I am using

 uxterm #uterm can also be used 

My code looks like this now:

proc = subprocess.Popen([‘uxterm’, ‘-e’, ‘test_aa.py’], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, preexec_fn=os.setsid) 

it work perfect. I can have other programs running in terminal windows, I can reboot and using .sh files bring all programs back to life again.

This is exactly what I was looking for :-)

Thanks everyone for help.