PIFACECAD : how to handle keys events btw 2 scripts ?

Hi all,

Proud new owner of a PiFace CAD, I'm trying to create a script that would "rule them all"... like a tiny OS... I explain

I'm trying to create a main script that would give a "menu like interface" using the Question Method, easily understandable and useable by new comers (like myself).

What I'm trying to achieve with this little project is to be able to use some of the exemples given with the PiFaceCAD (Sysinfo, hangman, weather, tweets...),

with an interface that could be ran straigth out of the box and easily understandable (clear & commented) so it could be tweaked and modified with no knowledge of python.

So the project (at least that's how I see it, I may be wrong), would be centered around a main scrypt (the "OS", here called MainExecute.py) that would display the menu like interface,

handle some keys events and launch other scripts/shell commands.

here is the code of MainExecute.py (the main script)...

#!/usr/bin/env python3

import subprocess
import pifacecad
import sys
PY3 = sys.version_info[0] >= 3
if not PY3:
    print("The script only works with `python3`, try using `python3 MainExecute.py`.")
    sys.exit(1)

from time import sleep
from pifacecad.tools.question import LCDQuestion

cad = pifacecad.PiFaceCAD()

GET_IP_CMD = "hostname --all-ip-addresses"
GET_INFOS_CMD = "python3 sysinfo.py"

def run_cmd(cmd):
    return subprocess.check_output(cmd, shell=True).decode('utf-8')

def get_my_ip():
    return run_cmd(GET_IP_CMD)[:-1]

def get_infos():
##    listener.deactivate()
    return run_cmd (GET_INFOS_CMD)


if __name__ == "__main__":
    
        question = LCDQuestion(question="What do u want?",answers=('My IP','Sys Infos','Hangman', 'Exit'))

        while True:
            answer_index = question.ask()
        
            if answer_index == 0:
                cad.lcd.clear()
                cad.lcd.write("{}\n".format(get_my_ip()))
                sleep(5)
                     
            if answer_index == 1:            
                cad.lcd.clear()
                get_infos()
                     
            else:
                cad.lcd.clear()
                cad.lcd.write("ByeBye")
                print("Byebye")

(since I'm not a programmer, I made this script by taking bits and pieces from different scripts found online, so this code isnt clean neither optimised, if you feel like "touching it up" to make it all nice and clean, feel free to do so )

so far, so good... the script launches, the shell commands work, I can get the IP, launch the Sysinfo script, navigate through the menu using the rocking switch BUT

I can't get the keys events interupts from button 0 to 3 to work properly (I've cleaned up the code of my "attempts" in the sake of readibility).

Here is the SysInfos.py script that's called by MainExecute.py (it's the just a slightly modified version of the script given as an exemple with the PifaceCAD...)

#!/usr/bin/env python3
import sys
import subprocess
import pifacecad
from time import sleep
##from threading import Barrier ## I was messing aroung with barrier to see what it does, havent figured it out yet... :/

cad = pifacecad.PiFaceCAD()

UPDATE_INTERVAL = 10  # 60 * 5 = 5 mins
GET_IP_CMD = "hostname --all-ip-addresses"
GET_TEMP_CMD = "/opt/vc/bin/vcgencmd measure_temp"
TOTAL_MEM_CMD = "free | grep 'Mem' | awk '{print $2}'"
USED_MEM_CMD = "free | grep '\-\/+' | awk '{print $3}'"

temperature_symbol = pifacecad.LCDBitmap(
    [0x4, 0x4, 0x4, 0x4, 0xe, 0xe, 0xe, 0x0])
memory_symbol = pifacecad.LCDBitmap(
    [0xe, 0x1f, 0xe, 0x1f, 0xe, 0x1f, 0xe, 0x0])
temp_symbol_index, memory_symbol_index = 0, 1

def run_cmd(cmd):
    return subprocess.check_output(cmd, shell=True).decode('utf-8')

def get_my_ip():
    return run_cmd(GET_IP_CMD)[:-1]

def get_my_temp():
    return run_cmd(GET_TEMP_CMD)[5:9]

def get_my_free_mem():
    total_mem = int(run_cmd(TOTAL_MEM_CMD))
    used_mem = int(run_cmd(USED_MEM_CMD))
    mem_perc = used_mem / total_mem
    return "{:.1%}".format(mem_perc)

def wait_for_ip():
    ip = ""
    while len(ip) <= 0:
        sleep(1)
        ip = get_my_ip()

def show_sysinfo():
    while True:
        cad.lcd.clear()
        cad.lcd.write("{}\n".format(get_my_ip()))
        cad.lcd.write_custom_bitmap(temp_symbol_index)
        cad.lcd.write(":{}C ".format(get_my_temp()))
        cad.lcd.write_custom_bitmap(memory_symbol_index)
        cad.lcd.write(":{}".format(get_my_free_mem()))
        sleep(UPDATE_INTERVAL)
##        sys.exit(0) ## doesnt quits the script, doesnt work 

if __name__ == "__main__":
    cad.lcd.blink_off()
    cad.lcd.cursor_off()

    if "clear" in sys.argv:
        cad.lcd.clear()
        cad.lcd.display_off()
        cad.lcd.backlight_off()
    else:
        cad.lcd.store_custom_bitmap(temp_symbol_index, temperature_symbol)
        cad.lcd.store_custom_bitmap(memory_symbol_index, memory_symbol)
        cad.lcd.backlight_on()
        cad.lcd.write("Waiting for IP..")
        wait_for_ip()
        show_sysinfo()

So, here are the reasons why I come before you :

I'd like to be able to use button 4 as a "quit/go back to menu" button (quits whatever the script is doing and go back to the begin of MainExecute.py) from "anywhere" (from a shell command acting like a CTRL+C, from another script... ).

And I'd like to be able to use buttons from 0 to 3, depending on the need of the running script/shell command (a press on btn0 would display the ipV6 adress when running the IP shell command, or would display some other infos while running SysInfos.py, for exemple...)

Sorry for the long thread, I could have summit it in few words by saying "I have 2 scripts, and I'd like to be able to quit 1 to go to the other by a press of a button", but I thought that giving you the whole picture would be better

thanks in advance all

AP