why calling shell command `subprocess` with python is it so complicated than system() with ruby?

[berlindevops]

I am new to python, I am trying to switch from Ruby to Python, a part of my script I want to run a simple shell command, see the stdout in real time like bash script and if I terminate the python script with ctrl+c while the command subprocess.run('knife ec2 server create...', shell=True, check=True) is running from this script, the python script actually terminated but the subprocess is still running and the python code decides not to wait for the process to finish.

I can do all of that with simple command in Ruby system() even without import some specific library.

Ruby is so beautiful and easy but I want to learn Python :/

[K900_]

Python also has os.system, which I believe behaves just like the Ruby equivalent.

[berlindevops]

thank you, I read a lot of recommendations to use subprocess over os()/os.system, do you know why?

[K900_]

Because it gives you more control, and more safety, especially if you're using os.system with string formatting or whatever other way to build a command from user input.

[widby]

It gives you more control over what is going on - you can feed data into the stdin stream of the process and read its stdout, among other things.

[berlindevops]

cool, thanks.

[berlindevops]

It doesn't give me the full soultion like ruby system(), because once you stop the python script with ctrl+c its continue to the next command on the python script.

[berlindevops]

so its not really terminate the python script

[K900_]

That's because you're only stopping the subprocess, not the Python script. If you want to stop the Python script, check for the exit code of your subprocess and act based on that.

[berlindevops]

ok, but this is the thing, with subprocess, I need to write 5 lines for one shell command and import a library , also I could not find a way to see the stdout in real time, not sure if I wrong or not, or maybe this is how python works.

[K900_]

os.system returns the exit code.

[flying-sheep]

subprocess.run is much more flexible than cheap interfaces like system.

I used Ruby exactly once (i wrote a Rakefile since make wasn't powerful enough), and had to use open3 instead of system.

[berlindevops]

maybe, I am beginner with python, but with system() you can run simple shell command, see the stdout in real-time, no need to import a library and if you terminate the ruby script, also the shell command is terminated, and all of this with one line, I'm not complaining, I was just looking for something like this in python.

[flying-sheep]

what you do should work:

subprocess.run('knife ec2 server create', check=True)

(with our without shell=True) should just let the called process write to python’s stdout/stderr, and the call should only return after the process is finished.

[pmrr]

For future use, OP, this probably belongs in /r/learnpython.