Upgrade sanity Docker image to debian:stretch

* Use latest pylint in Python 3.7 (they dropped support for PY2)
* Make latest pylint happy
* Forced to upgrade to shellcheck 0.4.4
* Make shellcheck 0.4.4 happy
* Adopt reviewers' advice to reduce global disabled rules

9 files changed, 14 insertions, 14 deletions

diff --git a/src/python/grpcio_tests/tests/_runner.py b/src/python/grpcio_tests/tests/_runner.py
index eaaa027e61..9ef0f17684 100644
--- a/src/python/grpcio_tests/tests/_runner.py
+++ b/src/python/grpcio_tests/tests/_runner.py
@@ -203,7 +203,7 @@ class Runner(object):
                             check_kill_self()
                             time.sleep(0)
                         case_thread.join()
-                except:
+                except:  # pylint: disable=try-except-raise
                     # re-raise the exception after forcing the with-block to end
                     raise
                 result.set_output(augmented_case.case, stdout_pipe.output(),
diff --git a/src/python/grpcio_tests/tests/protoc_plugin/_split_definitions_test.py b/src/python/grpcio_tests/tests/protoc_plugin/_split_definitions_test.py
index e21ea0010a..2b735526cb 100644
--- a/src/python/grpcio_tests/tests/protoc_plugin/_split_definitions_test.py
+++ b/src/python/grpcio_tests/tests/protoc_plugin/_split_definitions_test.py
@@ -144,7 +144,7 @@ class _ProtoBeforeGrpcProtocStyle(object):
                                        absolute_proto_file_names)
         pb2_grpc_protoc_exit_code = _protoc(
             proto_path, None, 'grpc_2_0', python_out, absolute_proto_file_names)
-        return pb2_protoc_exit_code, pb2_grpc_protoc_exit_code,
+        return pb2_protoc_exit_code, pb2_grpc_protoc_exit_code
 
 
 class _GrpcBeforeProtoProtocStyle(object):
@@ -160,7 +160,7 @@ class _GrpcBeforeProtoProtocStyle(object):
             proto_path, None, 'grpc_2_0', python_out, absolute_proto_file_names)
         pb2_protoc_exit_code = _protoc(proto_path, python_out, None, None,
                                        absolute_proto_file_names)
-        return pb2_grpc_protoc_exit_code, pb2_protoc_exit_code,
+        return pb2_grpc_protoc_exit_code, pb2_protoc_exit_code
 
 
 _PROTOC_STYLES = (
@@ -243,9 +243,9 @@ class _Test(six.with_metaclass(abc.ABCMeta, unittest.TestCase)):
 
     def _services_modules(self):
         if self.PROTOC_STYLE.grpc_in_pb2_expected():
-            return self._services_pb2, self._services_pb2_grpc,
+            return self._services_pb2, self._services_pb2_grpc
         else:
-            return self._services_pb2_grpc,
+            return (self._services_pb2_grpc,)
 
     def test_imported_attributes(self):
         self._protoc()
diff --git a/src/python/grpcio_tests/tests/protoc_plugin/beta_python_plugin_test.py b/src/python/grpcio_tests/tests/protoc_plugin/beta_python_plugin_test.py
index b46e53315e..43c90af6a7 100644
--- a/src/python/grpcio_tests/tests/protoc_plugin/beta_python_plugin_test.py
+++ b/src/python/grpcio_tests/tests/protoc_plugin/beta_python_plugin_test.py
@@ -223,7 +223,7 @@ def _CreateService(payload_pb2, responses_pb2, service_pb2):
     server.start()
     channel = implementations.insecure_channel('localhost', port)
     stub = getattr(service_pb2, STUB_FACTORY_IDENTIFIER)(channel)
-    yield servicer_methods, stub,
+    yield servicer_methods, stub
     server.stop(0)
 
 
diff --git a/src/python/grpcio_tests/tests/qps/benchmark_client.py b/src/python/grpcio_tests/tests/qps/benchmark_client.py
index 0488450740..fac0e44e5a 100644
--- a/src/python/grpcio_tests/tests/qps/benchmark_client.py
+++ b/src/python/grpcio_tests/tests/qps/benchmark_client.py
@@ -180,7 +180,7 @@ class StreamingSyncBenchmarkClient(BenchmarkClient):
         self._streams = [
             _SyncStream(self._stub, self._generic, self._request,
                         self._handle_response)
-            for _ in xrange(config.outstanding_rpcs_per_channel)
+            for _ in range(config.outstanding_rpcs_per_channel)
         ]
         self._curr_stream = 0
 
diff --git a/src/python/grpcio_tests/tests/qps/client_runner.py b/src/python/grpcio_tests/tests/qps/client_runner.py
index e79abab3c7..a57524c74e 100644
--- a/src/python/grpcio_tests/tests/qps/client_runner.py
+++ b/src/python/grpcio_tests/tests/qps/client_runner.py
@@ -77,7 +77,7 @@ class ClosedLoopClientRunner(ClientRunner):
     def start(self):
         self._is_running = True
         self._client.start()
-        for _ in xrange(self._request_count):
+        for _ in range(self._request_count):
             self._client.send_request()
 
     def stop(self):
diff --git a/src/python/grpcio_tests/tests/qps/worker_server.py b/src/python/grpcio_tests/tests/qps/worker_server.py
index 337a94b546..a03367ec63 100644
--- a/src/python/grpcio_tests/tests/qps/worker_server.py
+++ b/src/python/grpcio_tests/tests/qps/worker_server.py
@@ -109,7 +109,7 @@ class WorkerServer(worker_service_pb2_grpc.WorkerServiceServicer):
         start_time = time.time()
 
         # Create a client for each channel
-        for i in xrange(config.client_channels):
+        for i in range(config.client_channels):
             server = config.server_targets[i % len(config.server_targets)]
             runner = self._create_client_runner(server, config, qps_data)
             client_runners.append(runner)
diff --git a/src/python/grpcio_tests/tests/stress/client.py b/src/python/grpcio_tests/tests/stress/client.py
index 41f2e1b6c2..a318b308e6 100644
--- a/src/python/grpcio_tests/tests/stress/client.py
+++ b/src/python/grpcio_tests/tests/stress/client.py
@@ -132,9 +132,9 @@ def run_test(args):
     server.start()
 
     for test_server_target in test_server_targets:
-        for _ in xrange(args.num_channels_per_server):
+        for _ in range(args.num_channels_per_server):
             channel = _get_channel(test_server_target, args)
-            for _ in xrange(args.num_stubs_per_channel):
+            for _ in range(args.num_stubs_per_channel):
                 stub = test_pb2_grpc.TestServiceStub(channel)
                 runner = test_runner.TestRunner(stub, test_cases, hist,
                                                 exception_queue, stop_event)
diff --git a/src/python/grpcio_tests/tests/testing/_client_application.py b/src/python/grpcio_tests/tests/testing/_client_application.py
index 3ddeba2373..4d42df0389 100644
--- a/src/python/grpcio_tests/tests/testing/_client_application.py
+++ b/src/python/grpcio_tests/tests/testing/_client_application.py
@@ -130,9 +130,9 @@ def _run_stream_stream(stub):
     request_pipe = _Pipe()
     response_iterator = stub.StreStre(iter(request_pipe))
     request_pipe.add(_application_common.STREAM_STREAM_REQUEST)
-    first_responses = next(response_iterator), next(response_iterator),
+    first_responses = next(response_iterator), next(response_iterator)
     request_pipe.add(_application_common.STREAM_STREAM_REQUEST)
-    second_responses = next(response_iterator), next(response_iterator),
+    second_responses = next(response_iterator), next(response_iterator)
     request_pipe.close()
     try:
         next(response_iterator)
diff --git a/src/python/grpcio_tests/tests/unit/_from_grpc_import_star.py b/src/python/grpcio_tests/tests/unit/_from_grpc_import_star.py
index ad847ae03e..1ada25382d 100644
--- a/src/python/grpcio_tests/tests/unit/_from_grpc_import_star.py
+++ b/src/python/grpcio_tests/tests/unit/_from_grpc_import_star.py
@@ -14,7 +14,7 @@
 
 _BEFORE_IMPORT = tuple(globals())
 
-from grpc import *  # pylint: disable=wildcard-import
+from grpc import *  # pylint: disable=wildcard-import,unused-wildcard-import
 
 _AFTER_IMPORT = tuple(globals())