prevent script running twice consecutively - Python

Question

I have the following two Python scripts one sends a motor forward while the other script sends it backwards. Each script is operated by it's own button on a remote.

Script A

import RPi.GPIO as GPIO
from time import sleep
import json

GPIO.setmode(GPIO.BOARD)

GPIO.setup(22,GPIO.IN,pull_up_down=GPIO.PUD_UP)
GPIO.setup(19, GPIO.OUT)
GPIO.setup(21, GPIO.OUT)
GPIO.setup(23, GPIO.OUT)

abort = False
counter = 0

# read config
try:
    with open('config.json') as readfile:
        data = json.load(readfile)
    if data['lastrun'] == 'scripta':
        print('scripta already run')
        abort = True
except:
    pass

data = {'lastrun': 'scripta'}

if abort:
    quit()

print('turn motor clockwise')
pwm=GPIO.PWM(23, 100)

pwm.start(0)

GPIO.output(19, False)
GPIO.output(21, True)

pwm.ChangeDutyCycle(35)

GPIO.output(23, True)

sleep (0.5)

while True:
        input_state = GPIO.input(22)
        if input_state == False:
                counter = counter + 1
                print counter
                if counter == 2:
                        GPIO.output(23,GPIO.LOW)
                        exit()
                        GPIO.cleanup()
                sleep (0.3)

pwm.stop()

# write config
with open('config.json', 'w') as outfile:
    json.dump(data, outfile, sort_keys=True, indent=4)

GPIO.cleanup()

Script B

from time import sleep
import RPi.GPIO as GPIO
import json

GPIO.setmode(GPIO.BOARD)

GPIO.setup(22,GPIO.IN,pull_up_down=GPIO.PUD_UP)
GPIO.setup(19,GPIO.OUT)
GPIO.setup(21,GPIO.OUT)
GPIO.setup(23,GPIO.OUT)

abort = False
counter = 0

# read config
try:
    with open('config.json') as readfile:
        data = json.load(readfile)
    if data['lastrun'] == 'scriptb':
        print('scriptb already run')
        abort = True
except:
    pass

data = {'lastrun': 'scriptb'}

if abort:
    quit()

print('blind going up')
GPIO.output(19,GPIO.HIGH)
GPIO.output(21,GPIO.LOW)
GPIO.output(23,GPIO.HIGH)

while True:
        input_state = GPIO.input(22)
        if input_state == False:
                counter = counter + 1
                print counter
                if counter == 2:
                        GPIO.output(23,GPIO.LOW)
                        exit()
                        GPIO.cleanup()
                sleep (0.3)

# write config
with open('config.json', 'w') as outfile:
    json.dump(data, outfile, sort_keys=True, indent=4)

GPIO.cleanup()

The scripts include code designed to prevent a script running twice consecutively. Having run script A when I try to run it again it aborts as it should. Then I run script B which is fine however it doesn't abort on a second button press for some reason indicating that perhaps it isn't writing to the file as it should.

Many thanks!

Answer 1

How about using a config file to store the last run script:

scripta:

# scripta

import json

abort = False
# read config
try:
    with open('config.json') as readfile:
        data = json.load(readfile)
    if data['lastrun'] == 'scripta':
        print('scripta already run')
        abort = True
except:
    pass

data = {'lastrun': 'scripta'}

if abort:
    quit()

print('turn motor clockwise')

# write config
with open('config.json', 'w') as outfile:
    json.dump(data, outfile, sort_keys=True, indent=4)

scriptb:

# scriptb

import json

abort = False
# read config
try:
    with open('config.json') as readfile:
        data = json.load(readfile)
    if data['lastrun'] == 'scriptb':
        print('scriptb already run')
        abort = True
except:
    pass

data = {'lastrun': 'scriptb'}

if abort:
    quit()

print('turn motor anti-clockwise')

# write config
with open('config.json', 'w') as outfile:
    json.dump(data, outfile, sort_keys=True, indent=4)