build: support python 3.8 and 3.9 (#558)

* build: support python 3.8 amd 3.9

Refs: #555

* make 3.8 default python

Author: cguardia

packages/google-cloud-ndb/CONTRIBUTING.rst

@@ -23,8 +23,8 @@ 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 and 3.7
-  on both UNIX and Windows.
+- The feature must work fully on the following CPython versions:  2.7, 3.6
+  3.7, 3.8, and 3.9 on both UNIX and Windows.
 
 - The feature must not add unnecessary dependencies (where
   "unnecessary" is of course subjective, but new dependencies should
@@ -144,7 +144,7 @@ Running System Tests
 
   .. note::
 
-      System tests are only configured to run under Python 3.7. For
+      System tests are only configured to run under Python 3.8. 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
@@ -273,11 +273,17 @@ Supported Python Versions
 
 We support:
 
+-  `Python 2.7`_
 -  `Python 3.6`_
 -  `Python 3.7`_
+-  `Python 3.8`_
+-  `Python 3.9`_
 
+.. _Python 2.7: https://docs.python.org/2.7/
 .. _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/
 
 
 Supported versions can be found in our ``noxfile.py`` `config`_.

packages/google-cloud-ndb/README.md

@@ -22,4 +22,4 @@ run on other Python platforms as well.
 GA
 
 ### Officially Supported Python Versions
-Python 2.7 & Python 3.6-3.7
+Python 2.7 & Python 3.6, 3.7, 3.8, 3.9

packages/google-cloud-ndb/noxfile.py

@@ -24,10 +24,10 @@
 
 LOCAL_DEPS = ("google-cloud-core", "google-api-core")
 NOX_DIR = os.path.abspath(os.path.dirname(__file__))
-DEFAULT_INTERPRETER = "3.7"
-ALL_INTERPRETERS = ("2.7", "3.6", "3.7")
-PY3_INTERPRETERS = ("3.6", "3.7")
-MAJOR_INTERPRETERS = ("2.7", "3.7")
+DEFAULT_INTERPRETER = "3.8"
+ALL_INTERPRETERS = ("2.7", "3.6", "3.7", "3.8", "3.9")
+PY3_INTERPRETERS = ("3.6", "3.7", "3.8", "3.9")
+MAJOR_INTERPRETERS = ("2.7", "3.8")
 
 BLACK_VERSION = "black==20.8b1"
 
@@ -42,7 +42,7 @@ def unit(session):
     session.install("pytest", "pytest-cov")
     session.install("mock")
     session.install(".")
-    # THis variable is used to skip coverage by Python version
+    # This variable is used to skip coverage by Python version
     session.env["PY_VERSION"] = session.python[0]
     # Run py.test against the unit tests.
     run_args = ["pytest"]

packages/google-cloud-ndb/setup.py

@@ -55,6 +55,8 @@ def main():
             "Programming Language :: Python :: 3",
             "Programming Language :: Python :: 3.6",
             "Programming Language :: Python :: 3.7",
+            "Programming Language :: Python :: 3.8",
+            "Programming Language :: Python :: 3.9",
             "Programming Language :: Python :: 2",
             "Programming Language :: Python :: 2.7",
             "Operating System :: OS Independent",