Add --columns parameter to knnPerfTest.py for custom output selection

[rohit211-s]

Fixes #465

Changes

• Added --columns command-line argument to knnPerfTest.py
• Updated gradle runKnnPerfTest task to support -Pcolumns property
• Maintains backward compatibility - existing behavior unchanged when no columns specified

[dsmiley]

Thanks for contributing during the CoC hackathon! You have the honors of the first PR contribution :-)

[msokolov]

This looks cool. I am concerned about relying on gradle though -- I think typical usage is to run by python3 src/main/knnPerfTest.py . if we do that, columns will be None by default I think? Also, it would be nice to have a docstring to that --help would tell me what the columns are that I can select. I haven't really followed the work to add a gradle runner and / or use argparse, but I think argparse generally provides docs like that

[rohit211-s]

You're absolutely right about typical usage being direct Python execution Mike. The implementation works correctly for both approaches:

Direct Python usage (primary):
bash
python3 src/python/knnPerfTest.py --columns="recall,latency(ms)"

Gradle usage (optional convenience):
bash
./gradlew runKnnPerfTest -Pcolumns="recall,latency(ms)"

The core functionality is in the Python script - the gradle changes just pass through the parameter for users who prefer the gradle workflow (I generally use ./gradlew). When --columns is not provided, args.columns is None and the code falls back to default behavior, so direct Python usage works perfectly.

Would you prefer I remove the gradle changes and keep only the Python implementation?

[msokolov]

Would you prefer I remove the gradle changes and keep only the Python implementation?

No, I was just confused how this works at first. I must have missed some of the changes that I see now, not sure how ...

[msokolov]

can you show the output of knnPerfTest.py --help after this change?

[msokolov]

also, it looks like there's a failing test - maybe indentation or something?

[mikemccand]

also, it looks like there's a failing test - maybe indentation or something?

Try make tidy and see if it fixes the failure?

[rohit211-s]

can you show the output of knnPerfTest.py --help after this change?

Yeah sure mike

[msokolov]

still fails with:

# validate sources with ruff linter
/home/runner/work/luceneutil/luceneutil/.venv/bin/ruff check src/python
src/python/knnPerfTest.py:143:18: C401 Unnecessary generator (rewrite as a set comprehension)
    |
141 |     return set()
142 |
143 |   selected_set = set(col.strip() for col in selected_columns.split(","))
    |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ C401
144 |   all_headers = set(OUTPUT_HEADERS)
145 |   return all_headers - selected_set
    |
    = help: Rewrite as a set comprehension

Is there a way to run such tests locally? Maybe make does it?