grpc-python: Members of enum with value 0 not printed or converted to Json

[ascani...@gmail.com]

I have a message with an enum member. When the value is 0, it is not printed out or added to json with MessageToJson().

python -m grpc_tools.protoc -I . --python_out=. --grpc_python_out=. ./test_service.proto

>>> import test_service_pb2

>>> x = test_service_pb2.TestMsg()

>>> print (x)

>>> x.my_string = "abcd"

>>> x.my_enum = 1

>>> print (x)

my_string: "abcd"

my_enum: ENUMTYPE_ONE

>>> x.my_enum = 0

>>> print (xxy)

my_string: "abcd"

## what happened to my_enum: ENUMTYPE_ZERO ??

python --version 3.5.2

protobuf 3.1.0

grpcio-1.0.4

test_service.proto:

syntax = "proto3";

service TestService {

    rpc TestMethod (TestMsg) returns (TestMsg);

}

message TestMsg {

    string my_string = 1;

    EnumType my_enum = 2;

}

// -----------------------------

enum EnumType {

    ENUMTYPE_ZERO = 0;

    ENUMTYPE_ONE = 1;

}

[ascani...@gmail.com]

Sorry for the noise:  forgot about default values in protobuf.