fix(ndb): Drop support for Python 3.9

packages/google-cloud-ndb/CONTRIBUTING.rst

@@ -24,7 +24,7 @@ In order to add a feature to ``python-ndb``:
   documentation (in ``docs/``).
 
 - 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
@@ -259,14 +259,12 @@ 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/

packages/google-cloud-ndb/README.md

@@ -30,14 +30,14 @@ GA
 
 Our client libraries are compatible with all current [active][3] and [maintenance][4] versions of Python.
 
-Python >= 3.9
+Python >= 3.10
 
 [3]: https://devguide.python.org/devcycle/#in-development-main-branch
 [4]: https://devguide.python.org/devcycle/#maintenance-branches
 
 ### Unsupported Python Versions
 
-Python <= 3.8
+Python <= 3.9
 
 If you are using an [end-of-life][5]
 version of Python, we recommend that you update as soon as possible to an actively supported version.

packages/google-cloud-ndb/noxfile.py

@@ -29,7 +29,7 @@
 LOCAL_DEPS = ("google-api-core", "google-cloud-core")
 NOX_DIR = os.path.abspath(os.path.dirname(__file__))
 DEFAULT_INTERPRETER = "3.14"
-ALL_INTERPRETERS = ("3.9", "3.10", "3.11", "3.12", "3.13", "3.14")
+ALL_INTERPRETERS = ("3.10", "3.11", "3.12", "3.13", "3.14")
 CURRENT_DIRECTORY = pathlib.Path(__file__).parent.absolute()
 
 BLACK_VERSION = "black[jupyter]==23.7.0"
@@ -47,7 +47,6 @@
 
 nox.options.sessions = [
     "prerelease_deps",
-    "unit-3.9",
     "unit-3.10",
     "unit-3.11",
     "unit-3.12",
@@ -359,7 +358,7 @@ def docfx(session):
     )
 
 
-@nox.session(py="3.9")
+@nox.session(py="3.10")
 def doctest(session):
     # Install all dependencies.
     session.install(

packages/google-cloud-ndb/setup.py

@@ -44,7 +44,7 @@ def main():
         "google-cloud-datastore >= 2.16.0, != 2.20.2, < 3.0.0",
         "protobuf >= 4.25.8, < 8.0.0",
         "pymemcache >= 2.1.0, < 5.0.0",
-        "pytz >= 2018.3",
+        "pytz >= 2022.1",
         "redis >= 3.0.0, < 8.0.0",
     ]
 
@@ -68,7 +68,6 @@ def main():
             "License :: OSI Approved :: Apache Software License",
             "Programming Language :: Python",
             "Programming Language :: Python :: 3",
-            "Programming Language :: Python :: 3.9",
             "Programming Language :: Python :: 3.10",
             "Programming Language :: Python :: 3.11",
             "Programming Language :: Python :: 3.12",
@@ -81,7 +80,7 @@ def main():
         packages=packages,
         install_requires=dependencies,
         extras_require={},
-        python_requires=">=3.9",
+        python_requires=">=3.10",
         include_package_data=False,
         zip_safe=False,
     )

packages/google-cloud-ndb/testing/constraints-3.10.txt

@@ -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",
+# Then this file should have foo==1.14.0
+google-cloud-datastore==2.16.0
+google-api-core==2.11.0
+protobuf==4.25.8
+pymemcache==2.1.0
+redis==3.0.0
+pytz==2022.1
+# TODO(https://github.com/googleapis/python-ndb/issues/913) remove this dependency once six is no longer used in the codebase
+six==1.12.0