chore: release bigframes 2.40.0

[shuoweil]

PR created by the Librarian CLI to initialize a release. Merging this PR will auto trigger a release.

Librarian Version: v0.13.0
Language Image: us-central1-docker.pkg.dev/cloud-sdk-librarian-prod/images-prod/python-librarian-generator@sha256:234b9d1f2ddb057ed7ac6a38db0bf8163d839c65c6cf88ade52530cddebce59e

bigframes: v2.40.0

v2.40.0 (2026-05-13)

Features

• Add bigframes.execution_history API to track BigQuery jobs (feat: Add bigframes.execution_history API to track BigQuery jobs #16588) (fa20a740)

  import bigframes.pandas as bpd
  bpd.options.compute.enable_execution_history = True
  df = bpd.read_gbq("my_table")
  # ... perform operations ...
  history = bpd.execution_history
  print(history.jobs) # Access BigQuery job details for executed queries

• Implement ai.similarity and ai.embed for text embeddings and semantic similarity (feat(bigframes): implement ai.similarity #16771, feat(bigframes): implement ai.embed #16759) (d4afa2c8, fcb4579b)

  import bigframes.pandas as bpd
  # Generate embeddings
  df["embeddings"] = bpd.bigquery.ai.embed(df["text_col"])
  # Compute similarity
  df["similarity"] = bpd.bigquery.ai.similarity(df["embeddings_a"], df["embeddings_b"])

• Support hparam_range and hparam_candidates parameters for hyperparameter tuning in model creation (feat: add support for hparam_range and hparam_candidates to bigframes.bigquery.create_model #16640) (ca47835c)

• Update ai.score, ai.classify and ai.if_ parameters to match their SQL equivalents (feat(bigframes): update ai.score to match its SQL version #16919, feat(bigframes): add more params to ai.classify #16990, feat(bigframes): update ai.if_() params to match the SQL version #16857) (9f42fe14, e9c52b12, f3cb4ad0)

• Support unstable sorting in sort_values and sort_index (feat(bigframes): Support unstable sort_values, sort_index #16665) (bbdeb70f)

• Support loading Avro and ORC data formats (feat(bigframes): Support loading avro, orc data #16555) (6d46cba3)

• Add NumPy ufunc support directly on column expressions (feat(bigframes): Add numpy ufunc support to col expressions #16554) (2f792abd)

Bug Fixes

• Fix bugs compiling ambiguous ids and in subqueries (fix(bigframes): Fix bugs compiling ambiguous ids and in subqueries #16617) (479e44dd)

• BigFrames respects bq default region (fix: BigFrames respects bq default region #16933) (ef9945a5)

• avoid views when querying BigLake tables from SQL cells (fix: avoid views when querying BigLake tables from SQL cells #16562) (fdd3e0de)

• avoid copy argument warning in to_pandas (fix: avoid copy argument warning in to_pandas #16917) (fe5245b8)

Performance Improvements

• Improve write api upload throughput (perf(bigframes): Improve write api upload throughput #16641) (ef856b04)

Documentation

• Add docs to the to_csv methods of dataframe and series (docs(bigframes): Add docs to the to_csv methods of dataframe and series #16570) (a8fccefd)

[gemini-code-assist]

Code Review

This pull request updates the bigframes library to version 2.40.0, including version bumps across configuration files and the addition of release notes. It also toggles release_only_mode to false in the librarian configuration. Feedback was provided regarding the inclusion of unrelated Babel-related entries in the CHANGELOG.md that should be removed to maintain relevance.

[gemini-code-assist]

These changelog entries appear to be unrelated to the bigframes project. They reference Babel (JavaScript) components and link to the babel/babel repository. These should be removed to maintain a clean and relevant changelog for the Python package.

[shuoweil]

removed