bpo-15248: Emit a compiler warning when missed a comma before tuple or list. by serhiy-storchaka · Pull Request #11757

bpo-15248: Emit a compiler warning when missed a comma before tuple or list. by serhiy-storchaka · Pull Request #11757 · python/cpython

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This looks very cool!

As an additional comment/question: would it make sense to move the logic generating the type description from the expr_ty into a function on its own to limit duplication ? I gave it a try at https://pastebin.com/XLZ2B7Cq (not tested whatsoever).

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I like this!

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Love this! Just some suggestions on the error messages.

		case JoinedStr_kind:
		case FormattedValue_kind:
		return compiler_warn(c, "'%.200s' object is not callable, "
		"perhaps missed a comma?",

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“perhaps you missed a comma?”

Also use “;” instead of “,” on the previous line.

		case GeneratorExp_kind:
		case Lambda_kind:
		return compiler_warn(c, "'%.200s' object is not subscriptable, "
		"perhaps missed a comma?",

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Ditto.

Thank you @SylvainDe! I also thought about this type of simplification, but was hesitant. I initially implemented this idea independently, but then I seen your nice variant and borrowed it.