fix(sqlalchemy-bigquery): Drop support for Python 3.8 and 3.9 (googleapis#16956)

This PR updates \`sqlalchemy-bigquery\` to establish Python 3.10 as the
minimum supported version, dropping support for Python 3.7, 3.8, and
3.9.

### Changes

* Configuration: Updated \`setup.py\` and \`noxfile.py\` to require
Python 3.10+ and remove references to Python 3.8 and 3.9.
* Documentation: Updated \`README.rst\` and \`CONTRIBUTING.rst\` to
reflect supported Python versions (up to 3.14).
* Constraints: Transferred lower bounds to \`constraints-3.10.txt\` and
dropped \`constraints-3.8.txt\` and \`constraints-3.9.txt\`.
* Fixes: Bumped \`pyarrow\` to \`6.0.0\` and pinned \`alembic==1.7.7\`
to fix Python 3.10 compatibility issues.

Verified successfully with 318 passing unit tests under Python 3.10!

Fixes internal issue: http://b/482126936 🦕

Author: chalmerlowe

packages/sqlalchemy-bigquery/CONTRIBUTING.rst

@@ -22,7 +22,7 @@ In order to add a feature:
   documentation.
 
 - The feature must work fully on the following CPython versions:
-  3.9, 3.10, 3.11, 3.12, 3.13 and 3.14 on both UNIX and Windows.
+  3.10, 3.11, 3.12, 3.13 and 3.14 on both UNIX and Windows.
 
 - The feature must not add unnecessary dependencies (where
   "unnecessary" is of course subjective, but new dependencies should
@@ -148,7 +148,7 @@ Running System Tests
 
   .. note::
 
-      System tests are only configured to run under Python 3.9, 3.12, and 3.14.
+      System tests are only configured to run under Python 3.12 and 3.14.
       For expediency, we do not run them in older versions of Python 3.
 
   This alone will not run the tests. You'll need to change some local
@@ -195,11 +195,11 @@ configure them just like the System Tests.
 
    # Run all tests in a folder
    $ cd samples/snippets
-   $ nox -s py-3.9
+   $ nox -s py-3.10
 
    # Run a single sample test
    $ cd samples/snippets
-   $ nox -s py-3.9 -- -k <name of test>
+   $ nox -s py-3.10 -- -k <name of test>
 
 ********************************************
 Note About ``README`` as it pertains to PyPI
@@ -221,14 +221,12 @@ Supported Python Versions
 
 We support:
 
--  `Python 3.9`_
 -  `Python 3.10`_
 -  `Python 3.11`_
 -  `Python 3.12`_
 -  `Python 3.13`_
 -  `Python 3.14`_
 
-.. _Python 3.9: https://docs.python.org/3.9/
 .. _Python 3.10: https://docs.python.org/3.10/
 .. _Python 3.11: https://docs.python.org/3.11/
 .. _Python 3.12: https://docs.python.org/3.12/
@@ -241,17 +239,6 @@ Supported versions can be found in our ``noxfile.py`` `config`_.
 .. _config: https://github.com/googleapis/google-cloud-python/blob/main/packages/sqlalchemy-bigquery/noxfile.py
 
 
-We also explicitly decided to support Python 3 beginning with version 3.9.
-Reasons for this include:
-
--  Encouraging use of newest versions of Python 3
--  Taking the lead of `prominent`_ open-source `projects`_
--  `Unicode literal support`_ which allows for a cleaner codebase that
-   works in both Python 2 and Python 3
-
-.. _prominent: https://docs.djangoproject.com/en/1.9/faq/install/#what-python-version-can-i-use-with-django
-.. _projects: http://flask.pocoo.org/docs/0.10/python3/
-.. _Unicode literal support: https://www.python.org/dev/peps/pep-0414/
 
 **********
 Versioning

packages/sqlalchemy-bigquery/README.rst

@@ -51,11 +51,11 @@ dependencies.
 
 Supported Python Versions
 ^^^^^^^^^^^^^^^^^^^^^^^^^
-Python >= 3.9, <3.14
+Python >= 3.10, <= 3.14
 
 Unsupported Python Versions
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
-Python <= 3.7.
+Python <= 3.9
 
 
 Mac/Linux

packages/sqlalchemy-bigquery/noxfile.py

@@ -45,16 +45,13 @@
 DEFAULT_PYTHON_VERSION = "3.14"
 
 UNIT_TEST_PYTHON_VERSIONS: List[str] = [
-    "3.8",
-    "3.9",
     "3.10",
     "3.11",
     "3.12",
     "3.13",
     "3.14",
 ]
 ALL_PYTHON = list(UNIT_TEST_PYTHON_VERSIONS)
-ALL_PYTHON.extend(["3.7"])
 UNIT_TEST_STANDARD_DEPENDENCIES = [
     "mock",
     "asyncmock",
@@ -276,8 +273,6 @@ def install_unittest_dependencies(session, *constraints):
 def unit(session, protobuf_implementation, install_extras=True):
     # Install all test dependencies, then install this package in-place.
 
-    if session.python in ("3.7",):
-        session.skip("Python 3.7 is no longer supported")
     if protobuf_implementation == "cpp" and session.python in (
         "3.11",
         "3.12",

packages/sqlalchemy-bigquery/setup.py

@@ -64,7 +64,7 @@ def readme():
         "grpcio >= 1.47.0, < 2.0.0",
         "grpcio >= 1.49.1, < 2.0.0; python_version =='3.11'",
         "grpcio >= 1.75.1, < 2.0.0; python_version >= '3.14'",
-        "pyarrow >= 5.0.0",
+        "pyarrow >= 6.0.0",
     ],
 }
 
@@ -101,8 +101,6 @@ def readme():
         "License :: OSI Approved :: MIT License",
         "Programming Language :: Python",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.8",
-        "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: 3.10",
         "Programming Language :: Python :: 3.11",
         "Programming Language :: Python :: 3.12",
@@ -123,7 +121,7 @@ def readme():
         "sqlalchemy>=1.4.16,<3.0.0",
     ],
     extras_require=extras,
-    python_requires=">=3.8, <3.15",
+    python_requires=">=3.10, <3.15",
     tests_require=["packaging", "pytz"],
     entry_points={
         "sqlalchemy.dialects": ["bigquery = sqlalchemy_bigquery:BigQueryDialect"]

packages/sqlalchemy-bigquery/sqlalchemy_bigquery/__init__.py

@@ -22,7 +22,6 @@
 
 import warnings
 
-from . import _versions_helpers
 from ._types import (
     ARRAY,
     BIGNUMERIC,
@@ -44,16 +43,15 @@
 )
 from .base import BigQueryDialect, dialect
 from .version import __version__
+import sys
 
-sys_major, sys_minor, sys_micro = _versions_helpers.extract_runtime_version()
-
-# Now that support for Python 3.7 and 3.8 has been removed, we don't expect the
+# Now that support for Python 3.7, 3.8 and 3.9 has been removed, we don't expect the
 # following check to succeed. The warning is only included for robustness.
-if sys_major == 3 and sys_minor in (7, 8):  # pragma: NO COVER
+if sys.version_info < (3, 10):  # pragma: NO COVER
     warnings.warn(
-        "The python-bigquery-sqlalchemy library no longer supports Python 3.7 "
-        "and Python 3.8. "
-        f"Your Python version is {sys_major}.{sys_minor}.{sys_micro}. We "
+        "The python-bigquery-sqlalchemy library no longer supports Python 3.7, "
+        "3.8 and 3.9. "
+        f"Your Python version is {sys.version_info.major}.{sys.version_info.minor}.{sys.version_info.micro}. We "
         "recommend that you update soon to ensure ongoing support. For "
         "more details, see: [Google Cloud Client Libraries Supported Python Versions policy](https://cloud.google.com/python/docs/supported-python-versions)",
         FutureWarning,

packages/sqlalchemy-bigquery/sqlalchemy_bigquery/_versions_helpers.py

@@ -0,0 +1,15 @@
+# This constraints file is used to check that lower bounds
+# are correct in setup.py
+# List *all* library dependencies and extras in this file.
+# Pin the version to the lower bound.
+#
+# e.g., if setup.py has "foo >= 1.14.0, < 2.0.0dev",
+sqlalchemy==1.4.16
+google-auth==2.14.1
+google-cloud-bigquery==3.20.0
+google-cloud-bigquery-storage==2.18.0
+google-api-core==2.11.1
+grpcio==1.47.0
+numpy==1.26.4
+alembic==1.7.7
+pyarrow==6.0.0