[kz930]

What changes were proposed in this PR?

The Python that "Export to Python" writes carried notes meant for whoever maintains the generator: why a frame is copied, why a row is dropped before scoring, why an empty cell keeps its row. Someone running the exported script does not need them, and they made the script longer to read. This PR takes those comments out of the exported code in 24 operators, and keeps a one or two line note in Scala above the string where the reason is worth keeping.

• Machine learning: the sklearn estimators' shared training, testing and fit-and-score code, Linear Regression, and the Machine Learning Scorer.
• Hugging Face: Iris Logistic Regression, Sentiment Analysis, Spam SMS Detection, Text Summarization.
• Visualization: Bar, Box/Violin, Bubble, Bullet, Choropleth, Contour, Dendrogram, Gauge, Hierarchy, Histogram 2D, Icicle, Radar, Tree Plot, URL Visualizer.
• Unnest String.

Only comments go. The translator's own markers stay: the # [Operator] heading over each section, # --- Output ---, and the # TODO it writes for an operator it cannot export yet. The Python that operators run inside the engine is not touched.

Any related issues, documentation, discussions?

The comments came in with the export PRs #8365, #8367, #8368, #8504 and #8340.

#9035 also changes Unnest String's export. Whichever of the two merges second keeps the other's change.

How was this PR tested?

No generated statement changes, only comment lines. Running the verification suite before and after, the 1,098 scripts it generates for 142 operators are identical once comment lines and temporary paths are set aside, and none of them has an explanatory comment left. All of WorkflowOperator/test passes (2,912 tests), as do scalafmtCheck and scalafixAll --check.

Was this PR authored or co-authored using generative AI tooling?

Generated-by: Claude Code (Claude Opus 5.5)

🤖 Generated with Claude Code

[github-actions]

Automated Reviewer Suggestions

Based on the git blame history of the changed files, we recommend the following reviewers:

• Contributors with relevant context: @aglinxinyuan
  You can notify them by mentioning @aglinxinyuan in a comment.

[github-actions]

⚠️ Benchmark changes need a look

🟢 4 better · 🔴 4 worse · ⚪ 7 noise (<±5%) · 0 without baseline

Compared against main d79ac16 benchmarked on this same runner, so the delta is largely free of cross-runner hardware noise. The "7d avg" column still reflects the gh-pages dashboard. Treat <±5% as noise unless repeated.

Dashboard · Run

	config	throughput	MB/s	latency	max Δ latest / 7d
🔴	bs=10 sw=10 sl=64	382	0.233	26,144/32,621/32,621 us	🟢 -47.7% / 🔴 +131.6%
🔴	bs=100 sw=10 sl=64	820	0.501	117,980/142,586/142,586 us	🔴 +10.6% / 🔴 +47.9%
⚪	bs=1000 sw=10 sl=64	949	0.579	1,042,259/1,136,850/1,136,850 us	⚪ within ±5% / 🔴 +22.4%

Baseline details

Latest main d79ac16 from same runner

config	metric	PR	latest main	7d avg	Δ latest	Δ 7d
bs=10 sw=10 sl=64	throughput	382 tuples/sec	337 tuples/sec	888.52 tuples/sec	+13.4%	-57.0%
bs=10 sw=10 sl=64	MB/s	0.233 MB/s	0.206 MB/s	0.542 MB/s	+13.1%	-57.0%
bs=10 sw=10 sl=64	p50	26,144 us	22,168 us	11,467 us	+17.9%	+128.0%
bs=10 sw=10 sl=64	p95	32,621 us	62,431 us	14,087 us	-47.7%	+131.6%
bs=10 sw=10 sl=64	p99	32,621 us	62,431 us	17,519 us	-47.7%	+86.2%
bs=100 sw=10 sl=64	throughput	820 tuples/sec	864 tuples/sec	1,174 tuples/sec	-5.1%	-30.1%
bs=100 sw=10 sl=64	MB/s	0.501 MB/s	0.527 MB/s	0.716 MB/s	-4.9%	-30.1%
bs=100 sw=10 sl=64	p50	117,980 us	113,785 us	89,952 us	+3.7%	+31.2%
bs=100 sw=10 sl=64	p95	142,586 us	128,949 us	96,426 us	+10.6%	+47.9%
bs=100 sw=10 sl=64	p99	142,586 us	128,949 us	110,188 us	+10.6%	+29.4%
bs=1000 sw=10 sl=64	throughput	949 tuples/sec	971 tuples/sec	1,204 tuples/sec	-2.3%	-21.2%
bs=1000 sw=10 sl=64	MB/s	0.579 MB/s	0.593 MB/s	0.735 MB/s	-2.4%	-21.2%
bs=1000 sw=10 sl=64	p50	1,042,259 us	1,034,610 us	886,711 us	+0.7%	+17.5%
bs=1000 sw=10 sl=64	p95	1,136,850 us	1,095,979 us	928,644 us	+3.7%	+22.4%
bs=1000 sw=10 sl=64	p99	1,136,850 us	1,095,979 us	972,356 us	+3.7%	+16.9%

Raw CSV

config_idx,batch_size,schema_width,string_len,num_batches,total_ms,total_tuples,total_bytes,tuples_per_sec,mb_per_sec,lat_p50_us,lat_p95_us,lat_p99_us
0,10,10,64,20,523.98,200,128000,382,0.233,26144.18,32620.60,32620.60
1,100,10,64,20,2438.77,2000,1280000,820,0.501,117980.41,142586.02,142586.02
2,1000,10,64,20,21079.30,20000,12800000,949,0.579,1042259.42,1136849.99,1136849.99

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 92.04%. Comparing base (d79ac16) to head (89bd148).

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #9154      +/-   ##
============================================
- Coverage     92.05%   92.04%   -0.01%     
+ Complexity     5039     5038       -1     
============================================
  Files          1286     1286              
  Lines         55928    55917      -11     
  Branches       7138     7138              
============================================
- Hits          51483    51470      -13     
  Misses         2693     2693              
- Partials       1752     1754       +2     

Flag	Coverage Δ		*Carryforward flag
access-control-service	77.44% <ø> (ø)
agent-service	99.16% <ø> (ø)		Carriedforward from b94d04d
amber	86.54% <100.00%> (-0.01%)	⬇️
computing-unit-managing-service	64.02% <ø> (ø)
config-service	87.61% <ø> (ø)
file-service	82.29% <ø> (ø)
frontend	96.47% <ø> (-0.01%)	⬇️	Carriedforward from b94d04d
notebook-migration-service	83.77% <ø> (ø)
pyamber	98.54% <ø> (ø)		Carriedforward from b94d04d
workflow-compiling-service	74.25% <ø> (ø)

*This pull request uses carry forward flags. Click here to find out more.

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[aglinxinyuan]

LGTM!

[kz930]

@carloea2 This removes the explanatory comments that the merged export PRs left in exported Python, and keeps a short note in Scala where the reason matters. The generated statements are unchanged across all 1,098 verification scripts. Could you take a look?

[carloea2]

Reviewed all 24 changed files. A mechanical comparison after removing explanatory comment lines found no executable source changes. Required CI checks pass. I did not rerun the 1,098-script comparison.

[aglinxinyuan]

Please resolve the conflicts.

[kz930]

@aglinxinyuan Resolved by merging main. The only conflict was TreePlot's producesDataFrame override, which #9204 moved into the shared chart contract.