Tweak run_mypy.py to be more user-friendly

[jessegrabowski]

Very small changes to reflect how this script is used by developers:

• --verbose is now the default
• By default, "expected" failures are filtered. You can see all failures by passing a --show-expected flag.

Justifications:

1. I have never run this command without --verbose, so why not?
2. The way this script is used is to fix mypy problems with a specific PR. This requires fixing only the new failures. Unless we're actively working on cleaning up the code base, we're only interested in the new failures.

[jessegrabowski]

It was pointed out here that we should just be using --output json instead of manually parsing the mypy output, so I've also done that.

[Copilot]

Pull Request Overview

This PR refactors run_mypy.py to improve the developer experience by making verbose output the default and filtering out expected failures unless explicitly requested. The script now uses mypy's JSON output format instead of custom text parsing.

Key changes:

• Switched from custom text parsing to mypy's native JSON output format via pd.read_json()
• Made --verbose the default behavior (default=1) and added --show-expected flag to control failure filtering
• Updated error messages to guide users based on the new default behavior

Comments suppressed due to low confidence (1)

scripts/run_mypy.py:142

• The --groupby option help text mentions {file|errorcode|message} but the new code uses column names from mypy's JSON output. If the JSON output doesn't have an errorcode column (it likely has code instead based on line 164), then --groupby errorcode will fail. The help text should be updated to match the actual available columns in the DataFrame.

        "--groupby",
        default="file",
        help="How to group verbose output. One of {file|errorcode|message}.",

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[Copilot]

This counts the number of files with expected failures, not the number of individual errors. The message is misleading because it says "{count} errors in files" when it actually means "errors from {count} files". Consider rephrasing to: "In addition to these errors, errors from {count} files marked as 'expected failures' were also found."

Suggested change

	f"\nNote: In addition to these errors, {len(failing.intersection(expected_failing))} errors in files "
	f"\nNote: In addition to these errors, errors from {len(failing.intersection(expected_failing))} files "

[Copilot]

The help text for --verbose is now misleading. Since default=1 makes verbose mode enabled by default, the help text should reflect this. Consider changing it to something like "Verbose output is enabled by default. Pass --verbose 0 to suppress output." or simply removing this argument in favor of a --quiet flag.

Suggested change

	"--verbose", action="count", default=1, help="Pass this to print mypy output."
	"--verbose", action="count", default=1, help="Verbose output is enabled by default. Pass --verbose 0 to suppress output."

[michaelosthege]

Looks good to me 👍

[Armavica]

Ohh thank you for this change!