Protobuf Python Experiment

A Protobuf Python Experiment

*

Makefile

PIPENV=pipenv
PIP=pip
PROTO_DIR=proto
VENDOR_DIR=vendored

PROTO_SOURCES=$(wildcard *.proto)
PROTO_TARGETS=$(patsubst %.proto,$(PROTO_DIR)/%_pb2.py,$(PROTO_SOURCES))

all: vendorise gen-proto
run: test.py

vendorise: $(VENDOR_DIR)
$(VENDOR_DIR): requirements.txt
	$(PIPENV) run -- $(PIP) install -r "$<" --target "$@" --no-deps

.INTERMEDIATE: requirements.txt
Pipfile.lock requirements.txt: Pipfile
	$(PIPENV) lock -r >"$@"

gen-proto: $(PROTO_TARGETS)

$(PROTO_TARGETS): | $(PROTO_DIR)/
$(PROTO_DIR)/%_pb2.py: %.proto
	protoc --python_out='$(PROTO_DIR)' '$<'

$(PROTO_DIR)/:
	@mkdir -p "$@"

test.py: vendorise gen-proto
	./test.py

Pipfile

[[source]]

url = "https://pypi.python.org/simple"
verify_ssl = true
name = "pypi"


[packages]

protobuf = ">3.0"


[dev-packages]

test.py

#!/usr/bin/env python3

import os
import sys

# Add vendor directory to module search path
parent_dir = os.path.abspath(os.path.dirname(__file__))
vendor_dir = os.path.join(parent_dir, 'vendored')

sys.path.append(vendor_dir)

from proto import test_message1_pb2, test_message2_pb2
from google.protobuf import text_format
from google.protobuf import json_format

def first():
  print("First parser")

  a = test_message1_pb2.Smoke()
  a_parse_text = test_message1_pb2.Smoke()
  a_parse_json = test_message1_pb2.Smoke()

  a.jones = "Test"
  a.wales = 512

  a_text = text_format.MessageToString(a)
  a_json = json_format.MessageToJson(a)

  print("PB:\n{!r}\nText: {!r}\nJSON: {!r}".format(a, a_text, a_json))

  text_format.Merge(a_text, a_parse_text)
  print("Text parsed:\n{!r}".format(a_parse_text))

  json_format.Parse(a_json, a_parse_json)
  print("JSON parsed:\n{!r}".format(a_parse_json))

def second():
  print("Second parser")

  a = test_message2_pb2.Event()
  a.api.name = "eapr.event"
  a.api.version = "1.2.3"
  a.smoke.jones = "Woah!!"
  a.smoke.wales = 1024
  a.smoke.blown.is_it = True
  a.smoke.blown.texture = "rough"

  print("Event to JSON:\n{!s}".format(json_format.MessageToJson(a)))

first()
second()

print("DONE")

test_message1.proto

syntax = "proto3";

message Smoke {
  string jones = 1;
  int64 wales = 2;
  Blown blown = 3;
}

test_message2.proto

syntax = "proto3";

import "google/protobuf/api.proto";

message Event {
  google.protobuf.Api api = 1;
  Smoke smoke = 2;
}

message Smoke {
  string jones = 1;
  int64 wales = 2;
  Blown blown = 3;
}

message Blown {
  bool is_it = 1;
  string texture = 2;
}