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      1 # gRPC Python Server Reflection
      2 
      3 This document shows how to use gRPC Server Reflection in gRPC Python.
      4 Please see [C++ Server Reflection Tutorial](../server_reflection_tutorial.md)
      5 for general information and more examples how to use server reflection.
      6 
      7 ## Enable server reflection in Python servers
      8 
      9 gRPC Python Server Reflection is an add-on library.
     10 To use it, first install the [grpcio-reflection](https://pypi.org/project/grpcio-reflection/)
     11 PyPI package into your project.
     12 
     13 Note that with Python you need to manually register the service
     14 descriptors with the reflection service implementation when creating a server
     15 (this isn't necessary with e.g. C++ or Java)
     16 ```python
     17 # add the following import statement to use server reflection
     18 from grpc_reflection.v1alpha import reflection
     19 # ...
     20 def serve():
     21     server = grpc.server(futures.ThreadPoolExecutor(max_workers=10))
     22     helloworld_pb2_grpc.add_GreeterServicer_to_server(Greeter(), server)
     23     # the reflection service will be aware of "Greeter" and "ServerReflection" services.
     24     SERVICE_NAMES = (
     25         helloworld_pb2.DESCRIPTOR.services_by_name['Greeter'].full_name,
     26         reflection.SERVICE_NAME,
     27     )
     28     reflection.enable_server_reflection(SERVICE_NAMES, server)
     29     server.add_insecure_port('[::]:50051')
     30     server.start()
     31 ```
     32 
     33 Please see
     34 [greeter_server_with_reflection.py](https://github.com/grpc/grpc/blob/master/examples/python/helloworld/greeter_server_with_reflection.py)
     35 in the examples directory for the full example, which extends the gRPC [Python
     36 `Greeter` example](https://github.com/grpc/tree/master/examples/python/helloworld) on a
     37 reflection-enabled server.
     38 
     39 After starting the server, you can verify that the server reflection
     40 is working properly by using the [`grpc_cli` command line
     41 tool](https://github.com/grpc/grpc/blob/master/doc/command_line_tool.md):
     42 
     43  ```sh
     44   $ grpc_cli ls localhost:50051
     45   ```
     46 
     47   output:
     48   ```sh
     49   grpc.reflection.v1alpha.ServerReflection
     50   helloworld.Greeter
     51   ```
     52 
     53   For more examples and instructions how to use the `grpc_cli` tool,
     54   please refer to the [`grpc_cli` documentation](../command_line_tool.md)
     55   and the [C++ Server Reflection Tutorial](../server_reflection_tutorial.md).
     56 
     57 ## Additional Resources
     58 
     59 The [Server Reflection Protocol](../server-reflection.md) provides detailed
     60 information about how the server reflection works and describes the server reflection
     61 protocol in detail.
     62