pythonscikit-learnnarwhalspolarsafter-work
scikit-learn 1.9 after work: narwhals is a real dependency
scikit-learn 1.9.0 (2 Jun 2026, jeremiedbb) adds narwhals (>=2.0.1) so pandas and Polars set_output share one path after __dataframe__ deprecation. Experimental callbacks (ProgressBar, ScoringMonitor). Not a LightGBM/XGBoost roundup. Three things to try tonight. Not investment advice.