force quit python during thread - python

I'm trying to create a program that spams your screen with terminal windows using threading and would like to create a failsafe button that force quits python when a certain parameter is met. I've tried "os._exit()" and that does not work. I am looking for a way to destroy all threads and force quit python as if my program runs for too long it will crash my computer.
def spam():
for i in range(30):
if i % 10 == 0: # if i is divisible by 10, it pauses for comedic timing
time.sleep(2)
os.system('open -a Terminal .') # opens terminal window
playsound('/Users/omar/Downloads/boom.wav') # plays comical 'vine' funny meme audio
thread = multiprocessing.Process(target=spam) # creates a thread
thread.start()
if pyautogui.failSafeCheck() == True or pynput.keyboard.Controller().type == 'Keyboard':
os._exit() and thread.terminate()
spam() # function call

Related

How to stop a loop with keyboard.add_hotkey, while this loop is started by keyboard.add_hotkey?

The following code works perfectly, the loop can be stop by pressing esc:
import time
import keyboard
run = 1
def end():
global run
run = 0
print(run)
def do_stuff():
while run:
print('running')
time.sleep(0.5)
keyboard.add_hotkey('esc', end)
do_stuff()
But if I start this loop with another add_hotkey, I cannot stop it with esc anymore.
import time
import keyboard
run = 1
def end():
global run
run = 0
print(run)
def do_stuff():
while run:
print('running')
time.sleep(0.5)
keyboard.add_hotkey('esc', end)
# do_stuff()
keyboard.add_hotkey('enter', do_stuff)
keyboard.wait()
What should I do to stop this loop? I tried to replace the while run: with while not keyboard.is_pressed('esc'):. It can stop the loop if I hold the esc for a while. But it doesn't seem like a good solution.
=======================
updates:
the following works:
import keyboard
import threading
run = 1
def end():
global run
run = 0
print(run)
def do_stuff():
while run:
print('running')
time.sleep(0.5)
def new_do_stuff():
t = threading.Thread(target=do_stuff, name='LoopThread')
t.start()
keyboard.add_hotkey('esc', end)
keyboard.add_hotkey('enter', new_do_stuff)
keyboard.wait('esc')
Since in the second example you enter the do_stuff() loop through the hotkey and never leave the do_stuff() loop, the system is still captured in the hotkey command and is not listening for hotkeys anymore. You would have to find a way to leave the loop after the keyboard.add_hotkey('enter', do_stuff) command and enter it externally through another way, so the system listens for hotkey-entries again.
I'm not aware of the context you're using this in, but using some sort of a main-loop, that does nothing but wait for a flag to be set (it should be set when you get the hotkey interrupt) and then enters the do_stuff() loop seems like a way to solve it.

Correctly terminating a thread in Python

I'm not too familiar with threading, and probably not using it correctly, but I have a script that runs a speedtest a few times and prints the average. I'm trying to use threading to call a function which displays something while the tests are running.
Everything works fine unless I try to put input() at the end of the script to keep the console window open. It causes the thread to run continuously.
I'm looking for some direction in terminating a thread correctly. Also open to any better ways to do this.
import speedtest, time, sys, datetime
from threading import Thread
s = speedtest.Speedtest()
best = s.get_best_server()
def downloadTest(tries):
x=0
downloadList = []
for x in range(tries):
downSpeed = (s.download()/1000000)
downloadList.append(downSpeed)
x+=1
results_dict = s.results.dict()
global download_avg, isp
download_avg = (sum(downloadList)/len(downloadList))
download_avg = round(download_avg,1)
isp = (results_dict['client']['isp'])
print("")
print(isp)
print(download_avg)
def progress():
while True:
print('~ ',end='', flush=True)
time.sleep(1)
def start():
now=(datetime.datetime.today().replace(microsecond=0))
print(now)
d = Thread(target= downloadTest, args=(3,))
d.start()
d1 = Thread(target = progress)
d1.daemon = True
d1.start()
d.join()
start()
input("Complete...") # this causes progress thread to keep running
There is no reason for your thread to exit, which is why it does not terminate. A daemon thread normally terminates when your programm (all other threads) terminate, which does not happen in this as the last input does not quit.
In general it is a good idea to make a thread stop by itself, rather than forcefully killing it, so you would generally kill this kind of thread with a flag. Try changing the segment at the end to:
killflag = False
start()
killflag = True
input("Complete...")
and update the progress method to:
def progress():
while not killflag:
print('~ ',end='', flush=True)
time.sleep(1)

python loop(): raw_input() EOFError: EOF when reading a line

Here is script (/shutdown.py). It monitors button press and if button is pressed more than 3 seconds, it runs poweroff command.
#!/usr/bin/python
# Import the modules to send commands to the system and access GPIO pins
from subprocess import call
from time import sleep
import RPi.GPIO as gpio
import time
# Define a function to keep script running
def loop():
raw_input()
# Define a function to run when an interrupt is called
def shutdown(pin):
button_press_timer = 0
while True:
if (gpio.input(17) == False) : # while button is still pressed down
button_press_timer += 1 # keep counting until button is released
if button_press_timer == 3:
#print "powering off"
call('poweroff', shell=True)
sleep(1)
else: # button is released, figure out for how long
#print "Poga atlaista. nospiesta bija " + str(button_press_timer) + " sekundes"
#button_press_timer = 0
return
# sleep(1) # 1 sec delay so we can count seconds
# print "powering off"
gpio.setmode(gpio.BCM) # Use BCM GPIO numbers
gpio.setup(17, gpio.IN, pull_up_down=gpio.PUD_UP) # Set up GPIO 17 as an input
gpio.add_event_detect(17, gpio.FALLING, callback=shutdown, bouncetime=200) # Set up an interrupt to look for button presses
loop() # Run the loop function to keep script running
If I run script from console like /shutdown.py all is fine. Button press is detected and system shutdown is initialed. But if i add that script to /etc/rc.local (/shutdown.py &), then it fails at startup with this error:
Traceback (most recent call last):
File "/shutdown.py", line 35, in <module>
loop() # Run the loop function to keep script running
File "/shutdown.py", line 11, in loop
raw_input()
EOFError: EOF when reading a line
If I comment out loop() line, then there is no error and script does not run in background. I just start and exit and button press not detected. So, how i can run that script at startup and keep running in background?
EDIT
I am not python guru and i think that loop() is python internal function. Now i seen that it is defined function which calls raw_input(). That script I found and modified to fit my needs.
Thanks.
What you really need is a Python daemon which runs in the background. The raw_input method you are trying to use looks like an ugly hack to me.
Have a look at python-daemon package, which is meant exactly for your use case and is quite simple to use. There is also an updated fork with Python 3 support.
After installing python-daemon, add this line to the beginning of your script
import daemon
Then substitute the loop() call at the end of your script with this code:
with daemon.DaemonContext():
while True:
time.sleep(10)
This code is untested, but you get the idea.

python thread weird behavior

I have a timer function which I am calling it in another function like this
import time
import threading
def f():
while(True):
print "hello"
time.sleep(5)
def execute():
t = threading.Timer(5,f)
t.start()
command = ''
while command != 'exit':
command = raw_input()
if command == 'exit':
t.cancel()
Even if after entering "exit" command, the function is printing "hello"
I am not able to figure out Whats wrong with the code
class threading.Timer - cancel() - Doc-Link
Stop the timer, and cancel the execution of the timer’s action. This will only work if the timer is still in its waiting stage.
A very simple Version of what you are trying to accomplish could look like this.
import threading
_f_got_killed = threading.Event()
def f():
while(True):
print "hello"
_f_got_killed.wait(5)
if _f_got_killed.is_set():
break
def execute():
t = threading.Timer(5,f)
t.start()
command = ''
while command != 'exit':
command = raw_input()
if command == 'exit':
_f_got_killed.set()
t.cancel()
execute()
For forcefully killing a thread look at this:
Is there any way to kill a Thread in Python?
You are using cancel wrong. In http://docs.python.org/2/library/threading.html, it states: "Timers are started, as with threads, by calling their start() method. The timer can be stopped (before its action has begun) by calling the cancel() method. The interval the timer will wait before executing its action may not be exactly the same as the interval specified by the user."
In your code, if you try to use cancel after the timed thread has already begun its execution (it will in 5 seconds), cancel accomplishes nothing. The thread will remain in the while loop in f forever until you give it some sort of forced interrupt. So typing "exit" in the first 5 seconds after you run execute works. It will successfully stop the timer before the thread even begins. But after your timer stops and your thread starts executing the code in f, there will be no way to stop it through cancel.

Multiprocessing beside a main loop

I'm struggling with a issue for some time now.
I'm building a little script which uses a main loop. This is a process that needs some attention from the users. The user responds on the steps and than some magic happens with use of some functions
Beside this I want to spawn another process which monitors the computer system for some specific events like pressing specif keys. If these events occur then it will launch the same functions as when the user gives in the right values.
So I need to make two processes:
-The main loop (which allows user interaction)
-The background "event scanner", which searches for specific events and then reacts on it.
I try this by launching a main loop and a daemon multiprocessing process. The problem is that when I launch the background process it starts, but after that I does not launch the main loop.
I simplified everything a little to make it more clear:
import multiprocessing, sys, time
def main_loop():
while 1:
input = input('What kind of food do you like?')
print(input)
def test():
while 1:
time.sleep(1)
print('this should run in the background')
if __name__ == '__main__':
try:
print('hello!')
mProcess = multiprocessing.Process(target=test())
mProcess.daemon = True
mProcess.start()
#after starting main loop does not start while it prints out the test loop fine.
main_loop()
except:
sys.exit(0)
You should do
mProcess = multiprocessing.Process(target=test)
instead of
mProcess = multiprocessing.Process(target=test())
Your code actually calls test in the parent process, and that call never returns.
You can use the locking synchronization to have a better control over your program's flow. Curiously, the input function raise an EOF error, but I'm sure you can find a workaround.
import multiprocessing, sys, time
def main_loop(l):
time.sleep(4)
l.acquire()
# raise an EOFError, I don't know why .
#_input = input('What kind of food do you like?')
print(" raw input at 4 sec ")
l.release()
return
def test(l):
i=0
while i<8:
time.sleep(1)
l.acquire()
print('this should run in the background : ', i+1, 'sec')
l.release()
i+=1
return
if __name__ == '__main__':
lock = multiprocessing.Lock()
#try:
print('hello!')
mProcess = multiprocessing.Process(target=test, args = (lock, ) ).start()
inputProcess = multiprocessing.Process(target=main_loop, args = (lock,)).start()
#except:
#sys.exit(0)

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