change: Add Black formatting tool as dependency

As of this commit, Black formatting tool can be run with 'tox -e black-format'.
Black does not run as part of any automated process, yet.

Black is pulled in as a test dependency only if the Python version
is greater than 3.6, as the tool is not vended as part of any
earlier Python version.

Author: knakad

buildspec-release.yml

@@ -9,6 +9,9 @@ phases:
       # run linters
       - tox -e flake8,pylint
 
+      # run formatter
+      #- tox -e black-check # TODO: Uncomment once black formatting for all files has been pushed - knakad@
+
       # run package and docbuild checks
       - tox -e twine
       - tox -e sphinx

buildspec.yml

@@ -14,6 +14,9 @@ phases:
       - tox -e twine
       - tox -e sphinx
 
+      # run formatter
+      #- tox -e black-check # TODO: Uncomment once black formatting for all files has been pushed - knakad@
+
       # run unit tests
       - AWS_ACCESS_KEY_ID= AWS_SECRET_ACCESS_KEY= AWS_SESSION_TOKEN=
         AWS_CONTAINER_CREDENTIALS_RELATIVE_URI= AWS_DEFAULT_REGION=

setup.py

@@ -62,7 +62,7 @@ def read_version():
       extras_require={
           'test': ['tox', 'flake8', 'pytest==4.4.1', 'pytest-cov', 'pytest-rerunfailures',
                    'pytest-xdist', 'mock', 'tensorflow>=1.3.0', 'contextlib2',
-                   'awslogs', 'pandas']},
+                   'awslogs', 'pandas', 'black==19.3b0 ; python_version >= \'3.6\'']},
 
       entry_points={
           'console_scripts': ['sagemaker=sagemaker.cli.main:main'],

tox.ini

@@ -4,7 +4,7 @@
 # and then run "tox" from this directory.
 
 [tox]
-envlist = flake8,pylint,twine,sphinx,py27,py36
+envlist = flake8,pylint,twine,sphinx,py27,py36 # TODO: Add 'black-format' once black formatting for all files has been pushed - knakad@
 
 skip_missing_interpreters = False
 
@@ -112,3 +112,17 @@ deps =
 commands =
     pip install --exists-action=w -r requirements.txt
     sphinx-build -T -W -b html -d _build/doctrees-readthedocs -D language=en . _build/html
+
+[testenv:black-format]
+# Used during development (before committing) to format .py files.
+basepython = python3
+deps = black==19.3b0
+commands =
+    black -l 100 ./
+
+[testenv:black-check]
+# Used by automated build steps to check that all files are properly formatted.
+basepython = python3
+deps = black==19.3b0
+commands =
+    black -l 100 --check ./