fix: Drop Python 3.6 support (#829)

* chore: Drop Python 2 support

Cloud NDB is one of the final Cloud Client libraries to
support Python 2 and retaining support for it will prevent
us from updating to the newest version of the underlying
Datastore libraries.

Not considering this a breaking change because pip will respect
python_requires in setup.py and not install a version that doesn't
support it anymore.

* chore: Drop Python 3.6 support

3.6 is EOL upstream; we recommend using a supported
version of Python.

As with the previous PR to drop Python 2 support,
I don't consider this a breaking change because pip
will gracefully select the right version for the
Python version you are using.

Co-authored-by: Anthonios Partheniou <partheniou@google.com>

CONTRIBUTING.rst

@@ -23,7 +23,7 @@ In order to add a feature to ``python-ndb``:
 - The feature must be documented in both the API and narrative
   documentation (in ``docs/``).
 
-- The feature must work fully on the following CPython versions:  3.6
+- The feature must work fully on the following CPython versions:
   3.7, 3.8, 3.9 and 3.10 on both UNIX and Windows.
 
 - The feature must not add unnecessary dependencies (where
@@ -73,7 +73,7 @@ We use `nox <https://nox.readthedocs.io/en/latest/>`__ to instrument our tests.
 - To test your changes, run unit tests with ``nox``::
 
     $ nox -s unit-3.10
-    $ nox -s unit-3.6
+    $ nox -s unit-3.7
     $ ...
 
 .. nox: https://pypi.org/project/nox-automation/
@@ -247,13 +247,11 @@ Supported Python Versions
 
 We support:
 
--  `Python 3.6`_
 -  `Python 3.7`_
 -  `Python 3.8`_
 -  `Python 3.9`_
 -  `Python 3.10`_
 
-.. _Python 3.6: https://docs.python.org/3.6/
 .. _Python 3.7: https://docs.python.org/3.7/
 .. _Python 3.8: https://docs.python.org/3.8/
 .. _Python 3.9: https://docs.python.org/3.9/

README.md

@@ -22,11 +22,11 @@ run on other Python platforms as well.
 GA
 
 ### Officially Supported Python Versions
-Python 3.6, 3.7, 3.8, 3.9, 3.10
+Python 3.7, 3.8, 3.9, 3.10
 
 ### Unsupported Python Versions
 
-Python <= 3.5
+Python <= 3.6
 
 If you are using an `end-of-life`_
 version of Python, we recommend that you update as soon as possible to an actively supported version.

noxfile.py

@@ -26,8 +26,8 @@
 LOCAL_DEPS = ("google-api-core", "google-cloud-core")
 NOX_DIR = os.path.abspath(os.path.dirname(__file__))
 DEFAULT_INTERPRETER = "3.8"
-ALL_INTERPRETERS = ("3.6", "3.7", "3.8", "3.9", "3.10")
-PY3_INTERPRETERS = ("3.6", "3.7", "3.8", "3.9", "3.10")
+ALL_INTERPRETERS = ("3.7", "3.8", "3.9", "3.10")
+PY3_INTERPRETERS = ("3.7", "3.8", "3.9", "3.10")
 MAJOR_INTERPRETERS = "3.8"
 CURRENT_DIRECTORY = pathlib.Path(__file__).parent.absolute()
 

setup.py

@@ -57,7 +57,6 @@ def main():
             "License :: OSI Approved :: Apache Software License",
             "Programming Language :: Python",
             "Programming Language :: Python :: 3",
-            "Programming Language :: Python :: 3.6",
             "Programming Language :: Python :: 3.7",
             "Programming Language :: Python :: 3.8",
             "Programming Language :: Python :: 3.9",
@@ -70,7 +69,7 @@ def main():
         namespace_packages=["google", "google.cloud"],
         install_requires=dependencies,
         extras_require={},
-        python_requires=">=3.6",
+        python_requires=">=3.7",
         include_package_data=False,
         zip_safe=False,
     )