1# Copyright 2018 The gRPC Authors 2# 3# Licensed under the Apache License, Version 2.0 (the "License"); 4# you may not use this file except in compliance with the License. 5# You may obtain a copy of the License at 6# 7# http://www.apache.org/licenses/LICENSE-2.0 8# 9# Unless required by applicable law or agreed to in writing, software 10# distributed under the License is distributed on an "AS IS" BASIS, 11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12# See the License for the specific language governing permissions and 13# limitations under the License. 14"""Example gRPC client that gets/sets metadata (HTTP2 headers)""" 15 16from __future__ import print_function 17 18import logging 19 20import grpc 21import helloworld_pb2 22import helloworld_pb2_grpc 23 24 25def run(): 26 # NOTE(gRPC Python Team): .close() is possible on a channel and should be 27 # used in circumstances in which the with statement does not fit the needs 28 # of the code. 29 with grpc.insecure_channel("localhost:50051") as channel: 30 stub = helloworld_pb2_grpc.GreeterStub(channel) 31 response, call = stub.SayHello.with_call( 32 helloworld_pb2.HelloRequest(name="you"), 33 metadata=( 34 ("initial-metadata-1", "The value should be str"), 35 ( 36 "binary-metadata-bin", 37 b"With -bin surffix, the value can be bytes", 38 ), 39 ("accesstoken", "gRPC Python is great"), 40 ), 41 ) 42 43 print("Greeter client received: " + response.message) 44 for key, value in call.trailing_metadata(): 45 print( 46 "Greeter client received trailing metadata: key=%s value=%s" 47 % (key, value) 48 ) 49 50 51if __name__ == "__main__": 52 logging.basicConfig() 53 run() 54