Changes

💡 New Features

• [python-package] Add feature_names_in_ attribute for scikit-learn estimators (fixes #6279) @nicklamiller (#6310)
• [R-package]: add num_trees_per_iter, num_trees, and num_iter methods @mayer79 (#6500)

🔨 Breaking

• [c++] remove HDFS support (fixes #6436) @jameslamb (#6534)
• [ci] [python-package] run macOS x86_64 tests on macOS 12 (Monterey), stop manually setting macOS wheel tags @jameslamb (#6487)

🚀 Efficiency Improvement

• Avoid copy on Refit @cbourjau (#6478)

🐛 Bug Fixes

• [python-package] Correctly recognize LGBMClassifier(num_class=2, objective="multiclass") as multiclass classification @RektPunk (#6524)
• [cmake] Some improvements to handling of OpenMP on macOS @barracuda156 (#6489)
• [python-package] respect 'verbose' setting when using custom objective function (fixes #6014) @jameslamb (#6428)
• cmake: add missing lib_lightgbm_swig.so to lightgbmlib.jar on linux @shuttie (#6515)

📖 Documentation

• [docs] update GitHub Actions badges in README @StrikerRUS (#6570)
• [docs] Update badge for Link checks workflow @StrikerRUS (#6568)
• [python-package] [docs] Expand class docs for Dataset @Plenitude-ai (#6558)
• [docs] fix link to multiple OpenMP issue description @StrikerRUS (#6562)
• [docs] Add NuGet version badge @StrikerRUS (#6549)
• [docs] remove link to Roadmap (fixes #6556) @jameslamb (#6557)
• [docs] remove outdated docs from the repo @StrikerRUS (#6552)
• [docs] Add conda downloads badge @StrikerRUS (#6546)
• [docs] update and simplify installation docs @jameslamb (#6536)
• [doc] fix documentation for quantized training @shiyu1994 (#6528)
• [docs] fix FAQ markdown @StrikerRUS (#6521)
• [docs] [R-package] update cran-comments.md @jameslamb (#6499)
• [docs] remove pmml redirect, simplify some other docs @jameslamb (#6490)

🧰 Maintenance

• release v4.5.0 @jameslamb (#6538)
• [ci] modify CodeQL settings @jameslamb (#6563)
• [ci] revert clang-18 LD_LIBRARY_PATH workaround @jameslamb (#6559)
• [ci] [R-package] help linker find libstdc++.so.1 in clang18 job (fixes #6553) @jameslamb (#6554)
• [ci] update codeowners @jameslamb (#6542)
• [ci] [R-package] use --no-xattrs when re-tarring CRAN-style package @jameslamb (#6540)
• [ci] [R-package] add CI jobs covering more CRAN "additional checks", fix R_NO_REMAP warnings (fixes #6369) @jameslamb (#6523)
• [ci] [R-package] add arm64 macOS R-package CI job (fixes #6481) @jameslamb (#6494)
• [ci] restore aarch64 linux builds (fixes #6509) @jameslamb (#6527)
• [test][python] fix pandas DeprecationWarning about is_sparse function @StrikerRUS (#6532)
• fix cpp casting errors "Comparison of narrow type with wide type in loop condition" @StrikerRUS (#6533)
• [python-package] avoid overwriting dependencies via 'build-python.sh install' @jameslamb (#6526)
• [tests][python] fix nan in pandas bool column @StrikerRUS (#6530)
• Remove template parameters from copy constructor @hgminh95 (#6514)
• [ci] prevent lgb.model and lgb.pkl files being left behind after testing @nicklamiller (#6518)
• [ci] [R-package] run 'R CMD check' as a foreground task @jameslamb (#6508)
• [CMake] Use CMAKE_MSVC_RUNTIME_LIBRARY to apply /MT @hcho3 (#6484)
• [ci] resolve shellcheck errors in .ci/check_python_dists.sh @Kunal-Singh-Dadhwal (#6503)
• [ci] skip aarch64 linux job @jameslamb (#6517)
• [R-package] Use Rf_-prefixed versions of protect/unprotect @david-cortes (#6502)
• [ci] reduce repetition of BUILD_DIRECTORY in CI scripts @jameslamb (#6497)
• [ci] remove OpenMP / MKL workaround in CI jobs @jameslamb (#6496)
• [ci] [docs] fix link-checks job @jameslamb (#6495)
• [python-package] Change build settings to set strict-config to false @Jorricks (#6493)
• [ci] remove unnecessary package installations in CI @jameslamb (#6488)
• chore: update dataset_loader.cpp @eltociear (#6483)
• bump development version to 4.4.0.99 @jameslamb (#6485)