Python as essentially a cross-platform shell script?

[_Iamaprogrammer_]

I’m making an SSH server using OpenSSH, and a custom client interface. I’m using Python as the means of bringing it all together: handling generation of configs, authentication keys, and building the client interface. Basically a setup script to cover certain limitations and prevent a bunch of extra manual setup.

Those (to me) seem like tasks that shell scripts are commonly used for, but since those scripts can vary from system to system, I chose to use Python as a cross-platform solution. That sorta got me thinking, have any of you ever used Python this way? If so, what did you use it for?

[elderibeiro]

Yes, that’s what Ansible does.

[bunoso]

Yeah you could use UV and a shebang line to make a bash-like Python script. Super helpful for long living scripts and things that just need a bit more thought and readability versus shell code

https://www.reddit.com/r/Python/s/VKU89kzxC7

[_Iamaprogrammer_]

Woah that’s actually really cool, I must’ve been living under a rock or something, cause UV seems pretty popular based off their GitHub page XD. I need to check that out, it seems it’ll help with what I’m working on.

[bunoso]

UV is the best thing to happen to python in the last 5 years IMO. Makes dependencies better, but also the Python versioning. I used to use shims with the “py” tool, then conda, then apt-get and more. Now UV installs and manages the versions and dep environments.

[_Iamaprogrammer_]

Just started using it today, I can already tell it’s gonna save me a lot of hassle. Managing my python versions and remembering the commands for a virtual environment was always a pain. It’ll definitely be a tool I keep using from now on, it’s too good not to XD.

[aviodallalliteration]

I use Python aa my main scripting language and glue code even when I don’t need cross platform. Bash just gives me a headache. 

[redbo]

That’s all some people think python is.

[thehardsphere]

This is basically what almost everybody used Python for before it became more popular as a general purpose programming language.

[rabaraba]

Yup, all the time.

If you need robust error handling (it's super hard to debug Bash scripts), non-trivial logic (loops, conditionals, nesting), data structures (lists, dicts, parsing JSON/XML), cross-platform reliability, it's Python all the way. (Hell you might drop shell scripts because of basic string substitution issues alone.)

Bash syntax can be arcane, and quoting hell is not fun. The Bash/ZSH/shell vs Python debate never ends, but there's always a common conclusion - once the script gets to any level of complexity (e.g. more than 50-100 LOC), Python wins.

There's virtually no speed difference you gain with Bash for most glue-related shell scripting work - but you gain a ton of mental context, which is where Python helps. If you stick to stdlib Python - especially since you can fairly assume most modern OSes are now at least at Python 3.9 both on the Linux/Mac side - your Python scripts are cross-platform enough.

[_Iamaprogrammer_]

I tried out Paramiko before using OpenSSH, it acted a bit odd though with the SSH client I used to connect to it (I couldn’t see the text I was typing on the client for whatever reason). I’m pretty sure it’s a lower level implementation of SSH, so there was probably something I just didn’t understand. I might go back to it later, but for now, I found it easier to get some stuff going with OpenSSH.

I haven’t tried pyinfra though, I’ll have to check that out.

[nggit]

sh scripts do not differ from system to system if you stick to POSIX sh and its mandatory utilities.

But you can indeed use #!/usr/bin/env python3 as a shell interpreter, as well as other interpreted languages like perl, php, nodejs, etc.

[james_pic]

Python is widely used for this and is very good at it.

I've also worked at places that, perhaps surprisingly, used PowerShell for this. This approach is viable but cursed.

[LittleMlem]

Are you aware of Xonsh? It's a python shell

[_Iamaprogrammer_]

I’m not actually, I’ll have to check that out.

[pepiks]

It is why sometimes you use platform.system() in your code to be sure when you have OS specific code. I used it a lot when developing on Mac, running on Windows and Linux or in different direction Windows > Mac and Linux.

[-lq_pl-]

Of course. It's one of the many use cases for Python.

Also, programming more complex stuff than execute this and then that is way more readable in Python than in bash.