From 8234d14113f484c60ee8633dc060f8054adf3748 Mon Sep 17 00:00:00 2001
From: Nathaniel Manista <nathaniel@google.com>
Date: Tue, 12 Jun 2018 17:30:23 +0000
Subject: Close channels in examples

---
 examples/python/helloworld/greeter_client.py       |  9 ++++---
 .../interceptors/default_value/greeter_client.py   | 12 ++++++---
 .../python/interceptors/headers/greeter_client.py  | 12 ++++++---
 examples/python/multiplex/multiplex_client.py      | 31 ++++++++++++----------
 examples/python/route_guide/route_guide_client.py  | 23 +++++++++-------
 5 files changed, 52 insertions(+), 35 deletions(-)

(limited to 'examples/python')

diff --git a/examples/python/helloworld/greeter_client.py b/examples/python/helloworld/greeter_client.py
index a0aeb47bd7..24b49ac233 100644
--- a/examples/python/helloworld/greeter_client.py
+++ b/examples/python/helloworld/greeter_client.py
@@ -22,9 +22,12 @@ import helloworld_pb2_grpc
 
 
 def run():
-    channel = grpc.insecure_channel('localhost:50051')
-    stub = helloworld_pb2_grpc.GreeterStub(channel)
-    response = stub.SayHello(helloworld_pb2.HelloRequest(name='you'))
+    # NOTE(gRPC Python Team): .close() is possible on a channel and should be
+    # used in circumstances in which the with statement does not fit the needs
+    # of the code.
+    with grpc.insecure_channel('localhost:50051') as channel:
+        stub = helloworld_pb2_grpc.GreeterStub(channel)
+        response = stub.SayHello(helloworld_pb2.HelloRequest(name='you'))
     print("Greeter client received: " + response.message)
 
 
diff --git a/examples/python/interceptors/default_value/greeter_client.py b/examples/python/interceptors/default_value/greeter_client.py
index aba7571d83..da21ac68ec 100644
--- a/examples/python/interceptors/default_value/greeter_client.py
+++ b/examples/python/interceptors/default_value/greeter_client.py
@@ -27,10 +27,14 @@ def run():
         message='Hello from your local interceptor!')
     default_value_interceptor = default_value_client_interceptor.DefaultValueClientInterceptor(
         default_value)
-    channel = grpc.insecure_channel('localhost:50051')
-    channel = grpc.intercept_channel(channel, default_value_interceptor)
-    stub = helloworld_pb2_grpc.GreeterStub(channel)
-    response = stub.SayHello(helloworld_pb2.HelloRequest(name='you'))
+    # NOTE(gRPC Python Team): .close() is possible on a channel and should be
+    # used in circumstances in which the with statement does not fit the needs
+    # of the code.
+    with grpc.insecure_channel('localhost:50051') as channel:
+        intercept_channel = grpc.intercept_channel(channel,
+                                                   default_value_interceptor)
+        stub = helloworld_pb2_grpc.GreeterStub(intercept_channel)
+        response = stub.SayHello(helloworld_pb2.HelloRequest(name='you'))
     print("Greeter client received: " + response.message)
 
 
diff --git a/examples/python/interceptors/headers/greeter_client.py b/examples/python/interceptors/headers/greeter_client.py
index 2b0dd3e177..6a09a3b9c5 100644
--- a/examples/python/interceptors/headers/greeter_client.py
+++ b/examples/python/interceptors/headers/greeter_client.py
@@ -25,10 +25,14 @@ import header_manipulator_client_interceptor
 def run():
     header_adder_interceptor = header_manipulator_client_interceptor.header_adder_interceptor(
         'one-time-password', '42')
-    channel = grpc.insecure_channel('localhost:50051')
-    channel = grpc.intercept_channel(channel, header_adder_interceptor)
-    stub = helloworld_pb2_grpc.GreeterStub(channel)
-    response = stub.SayHello(helloworld_pb2.HelloRequest(name='you'))
+    # NOTE(gRPC Python Team): .close() is possible on a channel and should be
+    # used in circumstances in which the with statement does not fit the needs
+    # of the code.
+    with grpc.insecure_channel('localhost:50051') as channel:
+        intercept_channel = grpc.intercept_channel(channel,
+                                                   header_adder_interceptor)
+        stub = helloworld_pb2_grpc.GreeterStub(intercept_channel)
+        response = stub.SayHello(helloworld_pb2.HelloRequest(name='you'))
     print("Greeter client received: " + response.message)
 
 
diff --git a/examples/python/multiplex/multiplex_client.py b/examples/python/multiplex/multiplex_client.py
index 9baa10247d..19d39ce66e 100644
--- a/examples/python/multiplex/multiplex_client.py
+++ b/examples/python/multiplex/multiplex_client.py
@@ -106,20 +106,23 @@ def guide_route_chat(route_guide_stub):
 
 
 def run():
-    channel = grpc.insecure_channel('localhost:50051')
-    greeter_stub = helloworld_pb2_grpc.GreeterStub(channel)
-    route_guide_stub = route_guide_pb2_grpc.RouteGuideStub(channel)
-    greeter_response = greeter_stub.SayHello(
-        helloworld_pb2.HelloRequest(name='you'))
-    print("Greeter client received: " + greeter_response.message)
-    print("-------------- GetFeature --------------")
-    guide_get_feature(route_guide_stub)
-    print("-------------- ListFeatures --------------")
-    guide_list_features(route_guide_stub)
-    print("-------------- RecordRoute --------------")
-    guide_record_route(route_guide_stub)
-    print("-------------- RouteChat --------------")
-    guide_route_chat(route_guide_stub)
+    # NOTE(gRPC Python Team): .close() is possible on a channel and should be
+    # used in circumstances in which the with statement does not fit the needs
+    # of the code.
+    with grpc.insecure_channel('localhost:50051') as channel:
+        greeter_stub = helloworld_pb2_grpc.GreeterStub(channel)
+        route_guide_stub = route_guide_pb2_grpc.RouteGuideStub(channel)
+        greeter_response = greeter_stub.SayHello(
+            helloworld_pb2.HelloRequest(name='you'))
+        print("Greeter client received: " + greeter_response.message)
+        print("-------------- GetFeature --------------")
+        guide_get_feature(route_guide_stub)
+        print("-------------- ListFeatures --------------")
+        guide_list_features(route_guide_stub)
+        print("-------------- RecordRoute --------------")
+        guide_record_route(route_guide_stub)
+        print("-------------- RouteChat --------------")
+        guide_route_chat(route_guide_stub)
 
 
 if __name__ == '__main__':
diff --git a/examples/python/route_guide/route_guide_client.py b/examples/python/route_guide/route_guide_client.py
index f2d4317ef1..b4ff3239ba 100644
--- a/examples/python/route_guide/route_guide_client.py
+++ b/examples/python/route_guide/route_guide_client.py
@@ -100,16 +100,19 @@ def guide_route_chat(stub):
 
 
 def run():
-    channel = grpc.insecure_channel('localhost:50051')
-    stub = route_guide_pb2_grpc.RouteGuideStub(channel)
-    print("-------------- GetFeature --------------")
-    guide_get_feature(stub)
-    print("-------------- ListFeatures --------------")
-    guide_list_features(stub)
-    print("-------------- RecordRoute --------------")
-    guide_record_route(stub)
-    print("-------------- RouteChat --------------")
-    guide_route_chat(stub)
+    # NOTE(gRPC Python Team): .close() is possible on a channel and should be
+    # used in circumstances in which the with statement does not fit the needs
+    # of the code.
+    with grpc.insecure_channel('localhost:50051') as channel:
+        stub = route_guide_pb2_grpc.RouteGuideStub(channel)
+        print("-------------- GetFeature --------------")
+        guide_get_feature(stub)
+        print("-------------- ListFeatures --------------")
+        guide_list_features(stub)
+        print("-------------- RecordRoute --------------")
+        guide_record_route(stub)
+        print("-------------- RouteChat --------------")
+        guide_route_chat(stub)
 
 
 if __name__ == '__main__':
-- 
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