I currently have a Python program that calls a MATLAB script as batch like so:
matlab = QProcess()
matlab.start('matlab -noFigureWindows -batch "cd(users/script_directory/); MyScript.m;"')
#^ command to start MATLAB batch process in CMD
The issue I'm running into is that once this batch process starts, there's no way to kill it. So if my Python app gets force-closed, the MATLAB script keeps running and causes all sorts of issues, meaning I need to kill the process on app close.
I'm calling the MATLAB script as a QProcess and get the following message when I force-close the Python app before the MATLAB script finishes executing:
QProcess: Destroyed while process ("matlab") is still running.
With this, how do I stop the batch MATLAB process? Using 'ctrl-c' in CMD works for me sometimes to kill the process but I need it to be consistent to make the Python work right.
Similarly, can I just have it 'force quit' or 'restart' batch MATLAB or anything along those lines to clear all running processes?
A brute force way to kill it would be to just kill any matlab process via the process and system utilities library at the start of your application:
import psutil
for process in psutil.process_iter():
if process.name().lower() == 'matlab.exe':
process.terminate()
I wrote a c++ program a.out and tried to run the program by using subprocess module in python, called run.py. After running the script, I used top to check cpu usage and found that the run.py does not shown in the list while a.out is running.
What happened to run.py? Where is it?
It is sleeping waiting for your C++ program to exit. That is because you used subprocess.call.
You can use subprocess.Popen which doesn't wait unless you call its wait method if you need your Python program to continue doing something else while the program runs.
Is it possible to run a python script from another python script without wating for termination.
Parent process will terminate immediately after creation of child process.
I tried:
subprocess.Popen([sys.executable, "main.py"], stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE)
and also:
os.system(...)
If you know that the other Python script has a main method, you could simply in you code call that other script:
import main
...
exit(main.main())
But here the other script executes in the context of calling script. If you want to avoid it, you could use the os.exec... functions, by launching a new Python interpretor:
import os
...
os.execl(sys.executable, "python", 'main.py')
The exec family functions will replace (under Unix-Linux) the current Python interpretor with a new one.
You can just add & to start script in background:
import os
os.system('/path/to/script.sh &')
exit()
In this case launched shell script will continue working even after main Python script exits.
But keep in mind that it can cause zombie processes appearance in our system.
I need to kill all python scripts except one. Unfortunattely, all scripts have similar name "pythonw.exe". Difference in PID only.
First time, i don't need to leave one script alive, thats why i just kill all python scripts in system by taskkill /F /T /IM "python*" command.
But now, i have one script, that automates all other scripts. The script is my simple "testing system". It rewrite object script, start, stop and restart.
But my problem is multithreading in objective script (10 - 20 threads).
I don't know, how to kill all python threads, except automates one.
P.S.
I tried to get tasklist and PID of automates script, and killed all scripts, except that one, but it doesn't work (i don't know why)
P.P.S
OS: Windows XP
Python 2.7.8
My solution is place testing code in exe file. Now i can kill all python scripts, as previously. Maybe someone will offer another solution?
I wrote a program in IDLE to tokenize text files and it starts to tokeniza 349 text files! How can I stop it? How can I stop a running Python program?
You can also do it if you use the exit() function in your code. More ideally, you can do sys.exit(). sys.exit() which might terminate Python even if you are running things in parallel through the multiprocessing package.
Note: In order to use the sys.exit(), you must import it: import sys
To stop your program, just press Control + C.
If your program is running at an interactive console, pressing CTRL + C will raise a KeyboardInterrupt exception on the main thread.
If your Python program doesn't catch it, the KeyboardInterrupt will cause Python to exit. However, an except KeyboardInterrupt: block, or something like a bare except:, will prevent this mechanism from actually stopping the script from running.
Sometimes if KeyboardInterrupt is not working you can send a SIGBREAK signal instead; on Windows, CTRL + Pause/Break may be handled by the interpreter without generating a catchable KeyboardInterrupt exception.
However, these mechanisms mainly only work if the Python interpreter is running and responding to operating system events. If the Python interpreter is not responding for some reason, the most effective way is to terminate the entire operating system process that is running the interpreter. The mechanism for this varies by operating system.
In a Unix-style shell environment, you can press CTRL + Z to suspend whatever process is currently controlling the console. Once you get the shell prompt back, you can use jobs to list suspended jobs, and you can kill the first suspended job with kill %1. (If you want to start it running again, you can continue the job in the foreground by using fg %1; read your shell's manual on job control for more information.)
Alternatively, in a Unix or Unix-like environment, you can find the Python process's PID (process identifier) and kill it by PID. Use something like ps aux | grep python to find which Python processes are running, and then use kill <pid> to send a SIGTERM signal.
The kill command on Unix sends SIGTERM by default, and a Python program can install a signal handler for SIGTERM using the signal module. In theory, any signal handler for SIGTERM should shut down the process gracefully. But sometimes if the process is stuck (for example, blocked in an uninterruptable IO sleep state), a SIGTERM signal has no effect because the process can't even wake up to handle it.
To forcibly kill a process that isn't responding to signals, you need to send the SIGKILL signal, sometimes referred to as kill -9 because 9 is the numeric value of the SIGKILL constant. From the command line, you can use kill -KILL <pid> (or kill -9 <pid> for short) to send a SIGKILL and stop the process running immediately.
On Windows, you don't have the Unix system of process signals, but you can forcibly terminate a running process by using the TerminateProcess function. Interactively, the easiest way to do this is to open Task Manager, find the python.exe process that corresponds to your program, and click the "End Process" button. You can also use the taskkill command for similar purposes.
To stop a python script just press Ctrl + C.
Inside a script with exit(), you can do it.
You can do it in an interactive script with just exit.
You can use pkill -f name-of-the-python-script.
To stop a python script using the keyboard: Ctrl + C
To stop it using code (This has worked for me on Python 3) :
import os
os._exit(0)
you can also use:
import sys
sys.exit()
or:
exit()
or:
raise SystemExit
To stop a running program, use Ctrl+C to terminate the process.
To handle it programmatically in python, import the sys module and use sys.exit() where you want to terminate the program.
import sys
sys.exit()
Ctrl-Break it is more powerful than Ctrl-C
When I have a python script running on a linux terminal, CTRL+\ works. (not CRTL + C or D)
Ctrl+Z should do it, if you're caught in the python shell. Keep in mind that instances of the script could continue running in background, so under linux you have to kill the corresponding process.
exit() will kill the Kernel if you're in Jupyter Notebook so it's not a good idea. raise command will stop the program.
To stop your program, just press CTRL + D
or exit().
you can also use the Activity Monitor to stop the py process
Control+D works for me on Windows 10. Also, putting exit() at the end also works.
Windows solution: Control + C.
Macbook solution: Control (^) + C.
Another way is to open a terminal, type top, write down the PID of the process that you would like to kill and then type on the terminal: kill -9 <pid>
If you are working with Spyder, use CTRL+. and you will restart the kernel, also you will stop the program.
Try using:
Ctrl + Fn + S
or
Ctrl + Fn + B
Press Ctrl+Alt+Delete and Task Manager will pop up. Find the Python command running, right click on it and and click Stop or Kill.
If you are writing a script to process 349 files, but want to test with fewer, just write a nonexisting word like 'stop' in your list, which will cause a stop in the form of an exception. This avoids dialogs like do you want to kill your process if you use exit() or quit()