[lahirumaramba]

Summary

Implements the policy to drop End-of-Life (EoL) Python versions in minor releases, aligning firebase-admin with Google Cloud Python client libraries and google-api-core.

Adds firebase_admin/_python_version_support.py (adapted from google.api_core._python_version_support) and invokes check_python_version() once at package import time in firebase_admin/__init__.py.

Key Changes

• Runtime Python Version Support Check (firebase_admin/_python_version_support.py):
  • Matches google-api-core lifecycle defaults (deprecation_date = python_eol - 1 year, end_of_support_date = python_eol + 1 week) with no custom grace overrides.
  • Includes an explicit VersionInfo entry for Python 3.9 (PSF EoL 2025-10-05) alongside Python 3.10–3.14 so that the warning recommends upgrading to at least Python 3.11. With default end_of_support_date, both Python 3.9 and 3.10 (both past EoL) emit the PYTHON_VERSION_UNSUPPORTED FutureWarning ("You are using a non-supported Python version... upgrade to at least Python 3.11"), matching the upcoming removal of both 3.9 and 3.10 in the next minor release.
  • Emits FutureWarning (rather than DeprecationWarning, which Python hides by default outside __main__) so developers see the warning in logs when importing firebase_admin.
  • Invoked once at package import time in firebase_admin/__init__.py (_python_version_support.check_python_version()).
• Documentation (README.md):
  • Updates the Supported Python Versions section to note that Python 3.9 and 3.10 support is deprecated and will be dropped in an upcoming minor release, and recommends Python 3.11 or higher.
• Unit Tests (tests/test_python_version_support.py):
  • Adds 43 date-injected unit tests (today= parameter) covering Python 3.9, 3.10, supported versions (3.11–3.14), untracked older (3.8) and future (3.15, 40.0) versions, and deprecation_date / end_of_support_date overrides.

Proposed Release Note

Python 3.9 and 3.10 are deprecated (both past EOL). Importing firebase_admin on these versions now emits a FutureWarning. Support for both will be dropped in the next minor release; please upgrade to Python 3.11 or higher.

[gemini-code-assist]

Code Review

This pull request introduces a Python version support checking mechanism for the Firebase Admin Python SDK. It adds a new module _python_version_support.py that checks the running Python version against a list of tracked versions and issues deprecation, end-of-life, or unsupported warnings accordingly. The README.md is updated to reflect that Python 3.9 and 3.10 support is deprecated, and comprehensive tests are added in tests/test_python_version_support.py. The review feedback suggests improving the warning attribution by adding stacklevel=2 to the warnings.warn calls, and refactoring the min_python helper function to avoid grammatically awkward fallback messages.