Enable running Python formatting

.gitignore

@@ -8,6 +8,7 @@ objs
 # Python items
 cython_debug/
 python_build/
+python_format_venv/
 .coverage*
 .eggs
 htmlcov/

setup.cfg

@@ -11,3 +11,7 @@ inplace=1
 
 [build_package_protos]
 exclude=.*protoc_plugin/protoc_plugin_test\.proto$
+
+# Style settings
+[yapf]
+based_on_style = google

tools/distrib/pyformat_code.sh

@@ -0,0 +1,60 @@
+#!/bin/bash
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+set -ex
+
+# change to root directory
+cd $(dirname $0)/../..
+
+DIRS=src/python
+EXCLUSIONS='src/python/grpcio/grpc_*.py src/python/grpcio_health_checking/grpc_*.py src/python/grpcio_reflection/grpc_*.py src/python/grpcio_tests/grpc_*.py'
+
+VIRTUALENV=python_format_venv
+
+virtualenv $VIRTUALENV
+PYTHON=`realpath $VIRTUALENV/bin/python`
+$PYTHON -m pip install --upgrade futures yapf
+
+exclusion_args=""
+for exclusion in $EXCLUSIONS; do
+  exclusion_args="$exclusion_args --exclude $exclusion"
+done
+
+script_result=0
+for dir in $DIRS; do
+  tempdir=`mktemp -d`
+  cp -RT $dir $tempdir
+  $PYTHON -m yapf -i -r -p $exclusion_args $dir
+  if ! diff -rq $dir $tempdir; then
+    script_result=1
+  fi
+  rm -rf $tempdir
+done
+exit $script_result

tools/run_tests/sanity/sanity_tests.yaml

@@ -12,5 +12,6 @@
 - script: tools/distrib/check_trailing_newlines.sh
 - script: tools/distrib/check_nanopb_output.sh
 - script: tools/distrib/check_include_guards.py
+- script: tools/distrib/pyformat_code.sh
 - script: tools/distrib/python/check_grpcio_tools.py