generate grpc client and server code in python

pip install grpcio-tools

python -m grpc_tools.protoc -I. --python_out=. --grpc_python_out=. route_guide.proto

result:
	route_guide_pb2_grpc.py 
	route_guide_pb2.py
	content:
		classes for the messages defined in route_guide.proto
		classes for the service defined in route_guide.proto
			RouteGuideStub, which can be used by clients to invoke RouteGuide RPCs
			RouteGuideServicer, which defines the interface for implementations of the RouteGuide service
		a function for the service defined in route_guide.proto
			add_RouteGuideServicer_to_server, which adds a RouteGuideServicer to a grpc.Server

note:
	The 2 in pb2 indicates that the generated code is following Protocol Buffers Python API version 2.
		route_guide_pb2_grpc.py 
		route_guide_pb2.py
	Version 1 is obsolete. 
	It has no relation to the Protocol Buffers Language version, which is the one indicated by syntax = "proto3" or syntax = "proto2" in a .proto file.