GitHub Action to run codespell

[cclauss]

These GitHub Action tests would only pass AFTER #63 and #64 (or similar) are merged.

• Fix typos discovered by codespell #63
• Lint Python code with ruff #64

[creachadair]

I am not enthusiastic about adding these to the CI, since it means local tests will no longer match what the CI does without the user having to install these tools.

The codespell one seems OK I guess, as it's cosmetic, but the linter seems like overkill given how little the nearly-throwaway Python scripts in this repo change.

[cclauss]

% ruff check --select=ALL --statistics | sort -k2

 2	A001   	[ ] builtin-variable-shadowing
99	ANN001 	[ ] missing-type-function-argument
 1	ANN002 	[ ] missing-type-args
 1	ANN003 	[ ] missing-type-kwargs
82	ANN201 	[ ] missing-return-type-undocumented-public-function
11	ANN204 	[*] missing-return-type-special-method
 5	ARG001 	[ ] unused-function-argument
 1	B007   	[*] unused-loop-control-variable
 1	C400   	[*] unnecessary-generator-list
 1	C901   	[ ] complex-structure
 1	COM812 	[*] missing-trailing-comma
 7	D100   	[ ] undocumented-public-module
 5	D101   	[ ] undocumented-public-class
21	D102   	[ ] undocumented-public-method
54	D103   	[ ] undocumented-public-function
 4	D105   	[ ] undocumented-magic-method
 6	D107   	[ ] undocumented-public-init
 1	D400   	[*] missing-trailing-period
 3	D401   	[ ] non-imperative-mood
 1	D415   	[*] missing-terminal-punctuation
 2	E101   	[ ] mixed-spaces-and-tabs
 2	E401   	[*] multiple-imports-on-one-line
 4	E501   	[ ] line-too-long
 2	E701   	[ ] multiple-statements-on-one-line-colon
 1	EM101  	[*] raw-string-in-exception
 5	EM103  	[*] dot-format-in-exception
 4	ERA001 	[*] commented-out-code
 1	EXE001 	[ ] shebang-not-executable
 8	F401   	[*] unused-import
 2	FBT002 	[ ] boolean-default-value-positional-argument
 1	FLY002 	[*] static-join-to-f-string
 6	I001   	[*] unsorted-imports
 1	PERF401	[ ] manual-list-comprehension
 1	PLR0912	[ ] too-many-branches
 7	PLR1714	[*] repeated-equality-comparison
11	PLR2004	[ ] magic-value-comparison
 1	PLW2901	[ ] redefined-loop-name
 2	PTH110 	[ ] os-path-exists
 1	PTH113 	[ ] os-path-isfile
 4	PTH123 	[ ] builtin-open
45	Q000   	[*] bad-quotes-inline-string
 3	Q001   	[*] bad-quotes-multiline-string
 5	RET505 	[*] superfluous-else-return
 1	RUF005 	[*] collection-literal-concatenation
 1	S101   	[ ] assert
 6	S311   	[ ] suspicious-non-cryptographic-random-usage
 2	S605   	[ ] start-process-with-a-shell
 1	SIM103 	[*] needless-bool
 1	SIM108 	[*] if-else-block-instead-of-if-exp
 5	SIM109 	[*] compare-with-tuple
 1	SIM110 	[*] reimplemented-builtin
 1	SIM114 	[*] if-with-same-arms
 1	SIM115 	[ ] open-file-with-context-handler
14	T201   	[*] print
 1	TRY003 	[ ] raise-vanilla-args
 3	UP004  	[*] useless-object-inheritance
 2	UP008  	[*] super-call-with-parameters
 2	UP010  	[*] unnecessary-future-import
 3	UP015  	[*] redundant-open-modes
 1	UP030  	[*] format-literals
 8	UP031  	[ ] printf-string-formatting
14	UP032  	[*] f-string
[*] fixable with `ruff check --fix`

[creachadair]

Hm. If we add a false positive in the future, how will someone know this is where to look for the exceptions list?

I'm definitely sympathetic to the desire for this, and it did find some real fixes, but I'm not convinced this is worth its weight as an ongoing dependency.

[cclauss]

We could store config in pyproject.toml or close this PR.

[creachadair]

My concern there is: Given that the Python code here isn't really a "primary" artifact of the repo, I think it would be distracting to litter config files for Python-specific tools (or IDEs, or other ancillary things) into the repo. (Settings for a C linter, on the other hand, would probably be fine, since it's a C library 🙂)

Not that I couldn't be convinced otherwise, but I think I'd rather not add those kinds of files on that basis.

Perhaps a more practical solution would be to add a bit to the README. Why don't we leave the codespell bit hooked up as it is, and I can (separately) add a paragraph there.

[cclauss]

pyproject.toml

[tool.codespell]
ignore-words-list = "inout,numer,passt,statics"