python中的protobuf到json (Protobuf to json in python)

問題描述

python中的protobuf到json (Protobuf to json in python)

我有一個對象，我在 Python 中使用 protobuf 進行反序列化。當我打印該對象時，它看起來像一個 python 對象，但是當我嘗試將其轉換為 json 時，我遇到了各種各樣的問題。

例如，如果我使用 json.dumps() 我知道對象（從 protoc 生成的代碼）不包含 _ dict _ 錯誤。

如果我使用 jsonpickle 我獲取 UnicodeDecodeError: 'utf8' codec can't decode byte 0x9d in position 97: invalid start byte。

下面的測試代碼正在使用 jsonpickle 並出現上面顯示的錯誤。

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)

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).

方法 2:

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

方法 3:

You can also user SerializeToString.

org.SerializeToString()

方法 4:

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)

方法 5:

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

(by exHash、denis‑sumin、Kevin Hill、Shubham Kanyal、vr286、Nirav)

參考文件

1. Protobuf to json in python (CC BY‑SA 3.0/4.0)