Python 中 json 的 Protobuf

我有一个在 Python 中使用 protobuf反序列化的对象。当我打印对象时，它看起来像一个 python 对象，但是当我试图将它转换成 json时，我遇到了各种各样的问题。

例如，如果我使用 json.dumps()，我得到的对象(从协议生成的代码)不包含 _ 迪克特 _ error。

如果我用 jsonpickle 我得到 UnicodeDecodeError: 'utf8' codec can't decode byte 0x9d in position 97: invalid start byte。

下面的测试代码使用 jsonpickle，错误如上所示。

if len(sys.argv) < 2:
print ("Error: missing ser file")
sys.exit()
else :
fileLocation = sys.argv[1]


org = BuildOrgObject(fileLocation)


org = org.Deserialize()




#print (org)
jsonObj = jsonpickle.encode(org)
print (jsonObj)
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小开

If you need to go straight to json take a look at the protobuf-to-json library, but you'll have to install that manually.

But I would recommend that you use the protobuf-to-dict library instead for a few reasons:

  1. It is accessible from pypi so you can simply pip install protobuf-to-dict or include it in a requirements.txt
  2. dict can be converted to json and might be more useful than a json string
小开

I'd recommend using protobuf↔json converters from google's protobuf library:

from google.protobuf.json_format import MessageToJson


json_obj = MessageToJson(org)

You can also serialise the protobuf to a dictionary:

from google.protobuf.json_format import MessageToDict
dict_obj = MessageToDict(org)

Refer to the protobuf package API documentation: https://developers.google.com/protocol-buffers/docs/reference/python/ (see module google.protobuf.json_format).

小开

You can also user SerializeToString.

org.SerializeToString()
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If you are using an older version that doesn't has the preserving_proto_field_name field:

from google.protobuf.json_format import MessageToJson
def proto_to_json(proto_obj):
json_obj = MessageToJson(proto_obj):
json_obj = MessageToJso, including_default_value_fields=True)
# Change lowerCamelCase of google Json conversion to the snake_case as in original protobuf
dict_obj = dict((re.sub(r'(?<!^)(?=[A-Z])', '_', k).lower(),v) for k, v in json.loads(json_obj).items())
if hasattr(proto_obj, 'uuid'):
dict_obj["uuid"] = proto_obj.uuid.encode("hex")
return json.dumps(dict_obj, indent=4, sort_keys=True)
小开

Here's my function to convert a proto3 object to a JSON object (i.e. Python dictionary):

def protobuf_to_dict(proto_obj):
key_list = proto_obj.DESCRIPTOR.fields_by_name.keys()
d = {}
for key in key_list:
d[key] = getattr(proto_obj, key)
return d

Since the converters from Google's protobuf library don't seem to work in some cases with the 3.19 version, this function leverages the Descriptor class present on each Protobuf object.

Here, getattr(obj, string_attribute) returns the value given by obj.attribute


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