How to stop/terminate a python script from running? - python

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()

Related

CTRL+C not handled in python script when using su

I have a Python code like this.
try:
while some_cond_is_still_true:
....
except KeyboardInterrupt: # Handle CTRL+C
...
While the KeyboardInterrupt is handled fine if I run the python script by myself, it is not handled if I run it as another user using su, like this.
su <some_other_user> -c 'python myprogram.py <args>'
How can I solve this problem?
The su command creates a new interactive shell and executes the command inside it.
When you use option -c (--command) the su command creates a new session with the user indicated in the command. To solve this use the option --session-command.
In this case the command will be this:
su user_name --session-command 'python myprogram.py <args>'
in this case you should be able to catch CTRL+C interrupt.
What The Bndr said is true. To solve this problem you can use the signal module to register a new callback function that will be called at SIGTERM signal.
In it you can either raise a KeyboardInterrupt() or set a global variable that controls the program's flow to False.
You can also try registering the default callback again, which does raise the KeyboardInterrupt() exception.
This should make the newly spawned shell propagate the signal correctly. If it doesn't, then you should choose the shell which will launch the script through su, because something is wrong with the one called at this moment. Or check your execute line at the top of your script.
Try playing with it with combinations of calls to the script like:
#! /usr/bin/env python
or
#! /usr/bin/python
or
#! /bin/sh python
or
#! /bin/bash python
and so on, and see what works. This assumes your script is made executable and you do not have to call Python interpreter directly. If you plan to distribute your script though, be careful what you leave there. Different distributions will react differently and some even may not have the problem you are currently experiencing.
If you use su <user> -c ... so an other shell in the conext of the specified user will be established.
I think: if you hit CTRL+C it depends on the shell, if the interrupt signal will reach the python scripts.
Try su <user> -c 'watch ls' to see, if CTRL + C will stop watching ls.
Not sure, what you trying to do with your script, but if you "only" like to abort an running script, you can do the following (alternatively to CTRL + C):
Stop this process (the users shell process) by pressing CRTL + Z. The Job number and the stopped process is displayed.
Now you can kill the process using the job number, like kill %1

Python: Quit IDLE after Script running

Is it possible to somehow quit Python IDLE under Windows from within my python code/script at the end after running?
I tried something like:
import sys
sys.exit(0) # or exit(1)
didn't work. Probably only quits the current "process" of the running python script.
Thanks a lot
If you can run IDLE from the command line (or edit your shortcut), I found this in the IDLE help.
If IDLE is started with the -n command line switch it will run in a
single process and will not create the subprocess which runs the RPC
Python execution server.
Which seems to imply that the script is running inside IDLE. I did a quick test script, and calling exit() brought up a box asking to kill the program. Clicked yes, and the script and IDLE both quit. Hope that can help.
This will do exactly what you want. No prompt.
import os
os.system("taskkill /f /im pythonw.exe")
To quit Python IDLE under Windows from within a python code/script without a further prompt, try:
parent_pid = os.getppid() # Get parent's process id
parent_process = None
for proc in psutil.process_iter(attrs=['pid']): # Check all processes
if proc.pid == parent_pid: # Parent's Process class
parent_process = proc
break
if parent_process is not None:
parent_process.kill() # Kill the parent's process
This works with IDLE, PyCharm and even the command line in Windows.

Is there a way I can close an exe from python

I am trying to launch an exe from my python script using
subprocess
but I want to close/kill it from python script too. Is there any way I can accomplish stopping an exe from python?
PS: My executable stops when I do Alt+F4. I basically want to emulate Alt+F4 programmatically in python.
Sure, you want to call Popen.terminate() or Popen.kill() on the subprocess. e.g.:
p = subprocess.Popen(['path/to/long/runnning/process', 'arg1', 'arg2'])
...
p.terminate() # kill the process.
Popen.terminate is a little more gentle -- On POSIX OSs, it'll give the program a chance to handle the signal and do some cleanup vs. kill which will try to destroy the process immediately.

Sending SIGINT (Ctrl-C) to program running in Eclipse Console

I have setup a run configuration in Eclipse and need to send SIGINT (Ctrl+C) to the program. There is cleanup code in the program that runs after SIGINT, so pressing Eclipse's "Terminate" buttons won't work (they send SIGKILL I think). Typing CTRL+C into the Console also doesn't work.
How do I send SIGINT to a process running inside an Eclipse Console?
(FWIW I am running a Twisted daemon and need Twisted to shutdown correctly, which only occurs on SIGINT)
If you can determine the process with a utility such as ps, you can use kill to send it a SIGINT. The program will likely be a child process of eclipse.
kill -s INT <pid>
You can send the command via one line:
kill -SIGINT $(ps aux | grep ProgrammName | grep -v grep | awk '{print $2}')
Get the process id and than send the sigint signal
That still seems to be an open issue:
https://bugs.eclipse.org/bugs/show_bug.cgi?id=38016
Just for the sake of completeness: If you came here to find a way to terminate a read line from System.in,
Ctrl + Z worked for me (on Windows).
in some versions, you can do the following.
In the Debug perspective, you can open a view called "Signals"
(Window/Show View/Signals" or Left-Bottom Icon).
You will get a list of all supported signals. Right-click and "Resume
with Signal" will give you the result you need.
I'm making an answer out of a modification of Artur Czajka's comment.
You can use pkill -SIGINT -f ProgramName. Explanation: pkill is similar to killall, -SIGINT states the signal to be used, -f makes it work better in this case (it will look through arguments and stuff instead of just the command name), and ProgramName is the target for pkill.

os.system('exit') in python

My friend is in a macOS environment and he wanted to call os.system('exit') at the end of his python script to make the terminal close. It doesn't. This doesn't surprise me but I would like to know what exactly is going on between the python script and the terminal when this call is made.
In my mental simulation the terminal should have to tell you that there are still running jobs, but that doesn't happen either.
As a side question : will some less common terminals close when a process calls this?
read the help:
Execute the command (a string) in a subshell.
A subshell is launched, and exit is run in that subshell.
To exit the enclosing terminal, you have to kill the parent. One way to do it is:
os.system("kill -9 %d"%(os.getppid())
The system function starts another shell to execute a command. So in this case your Python scripts starts a shell and runs "exit" command in there, which makes that process exit. However, the Python script itself, including a terminal where it is running, continues to run. If the intent is to kill the terminal, you have to get the parent process ID and send a signal requesting it to stop. That will kill both Python script and a terminal.
Remember that system first spawns/forks a sub-shell to execute its commands. In effect, you are asking only the sub-shell to exit.

Categories

Resources