Consider promoting platform.system over sys.platform and os.name

[NeilGirdhar]

See this explanation.

[real-or-random]

I disagree. Different methods have different purposes. As stated in the linked post, if you only care whether you're on posix or not, os.name == "posix" is the right thing to do.

[NeilGirdhar]

I disagree. Different methods have different purposes. As stated in the linked post, if you only care whether you're on posix or not, os.name == "posix" is the right thing to do.

Why not do platform.system() in {'Linux', 'Darwin'}? It's easier to understand, it's easier to alter if what you're checking changes, and it doesn't depend on what future Python versions do with "OS specific modules".

[real-or-random]

Why not do platform.system() in {'Linux', 'Darwin'}?

This misses Android, iOS, and potentially FreeBSD.

It's just a different check. If I want to know how to interpret the os.popen return code, I may want to know whether I'm on a POSIX system or not, and the straightforward way to check this is os.name == "posix".

[NeilGirdhar]

Got it, thanks. Does sys.platform have common uses too? It seems like most people will just check if it startswith something they know?

[MichaReiser]

sys.platforms is used and understood by type checkers whereas os.platform isn't (but some type checkers do support it, e.g. Pyright).

A use case where you want to use sys.platform is when checking for specific APIs, e.g. https://docs.python.org/3/library/sys.html#sys.activate_stack_trampoline which is only available on linux and not all posix systems.

[NeilGirdhar]

sys.platforms is used and understood by type checkers whereas os.platform isn't (but some type checkers do support it, e.g. Pyright).

A use case where you want to use sys.platform is when checking for specific APIs, e.g. https://docs.python.org/3/library/sys.html#sys.activate_stack_trampoline which is only available on linux and not all posix systems.

How would you check that? Wouldn't platform.system() == 'Linux' be what you want? As opposed to sys.platform.startswith('linux'), which seems much worse.

[MichaReiser]

I'd use sys.platform == "linux"? startswith shouldn't be necessary anymore because of

Changed in version 3.3: On Linux, sys.platform doesn’t contain the major version anymore. It is always 'linux', instead of 'linux2' or 'linux3'.

[NeilGirdhar]

Okay. I'm not sure if it's possible, but I think it would be good to come up with canonical ways of accomplishing various tasks and have Ruff nudge users towards these ways. If sys.platform == 'linux' is better than platform.system() == 'Linux', (or vice versa), it would be good to nudge everyone to write the same idea in the same way.