问当我试图解析一个包含重复元素的字典结构时，我得到了一个错误"CMessage‘对象不适用于'str’对象“

EN

msg0=MsgGrpType.MsgType(subject="test_subject0")
msg1=MsgGrpType.MsgType(subject="test_subject1")
msg2=MsgGrpType.MsgType(subject="test_subject3")
msgGrp = MsgGrpType(flow="BOALF", msg=[msg0,msg1,msg2], pub_ts=datetime.datetime.now().isoformat())
msgDict = google.protobuf.json_format.MessageToDict(msgGrp)
result = ParseDict(msgDict, MsgGrpType, ignore_unknown_fields=True) # Crashes
pprint.pprint(result)

{'flow': 'BOALF',
 'msg': [{'subject': 'test_subject0'},
         {'subject': 'test_subject1'},
         {'subject': 'test_subject3'}],
 'pubTs': '2021-07-19T13:18:40.263824'}

self = <google.protobuf.json_format._Parser object at 0x0000020177A3F2E0>
js = {'flow': 'BOALF', 'msg': [{'subject': 'test_subject0'}, {'subject': 'test_subject1'}, {'subject': 'test_subject3'}], 'pubTs': '2021-07-19T13:18:40.263824'}
message = <class 'com_elexeon_boalf_pb2.MsgGrpType'>

    def _ConvertFieldValuePair(self, js, message):
      """Convert field value pairs into regular message.
    
      Args:
        js: A JSON object to convert the field value pairs.
        message: A regular protocol message to record the data.
    
      Raises:
        ParseError: In case of problems converting.
      """
      names = []
      message_descriptor = message.DESCRIPTOR
      fields_by_json_name = dict((f.json_name, f)
                                 for f in message_descriptor.fields)
      for name in js:
        try:
          field = fields_by_json_name.get(name, None)
          if not field:
            field = message_descriptor.fields_by_name.get(name, None)
          if not field and _VALID_EXTENSION_NAME.match(name):
            if not message_descriptor.is_extendable:
              raise ParseError('Message type {0} does not have extensions'.format(
                  message_descriptor.full_name))
            identifier = name[1:-1]  # strip [] brackets
            # pylint: disable=protected-access
            field = message.Extensions._FindExtensionByName(identifier)
            # pylint: enable=protected-access
            if not field:
              # Try looking for extension by the message type name, dropping the
              # field name following the final . separator in full_name.
              identifier = '.'.join(identifier.split('.')[:-1])
              # pylint: disable=protected-access
              field = message.Extensions._FindExtensionByName(identifier)
              # pylint: enable=protected-access
          if not field:
            if self.ignore_unknown_fields:
              continue
            raise ParseError(
                ('Message type "{0}" has no field named "{1}".\n'
                 ' Available Fields(except extensions): {2}').format(
                     message_descriptor.full_name, name,
                     [f.json_name for f in message_descriptor.fields]))
          if name in names:
            raise ParseError('Message type "{0}" should not have multiple '
                             '"{1}" fields.'.format(
                                 message.DESCRIPTOR.full_name, name))
          names.append(name)
          value = js[name]
          # Check no other oneof field is parsed.
          if field.containing_oneof is not None and value is not None:
            oneof_name = field.containing_oneof.name
            if oneof_name in names:
              raise ParseError('Message type "{0}" should not have multiple '
                               '"{1}" oneof fields.'.format(
                                   message.DESCRIPTOR.full_name, oneof_name))
            names.append(oneof_name)
    
          if value is None:
            if (field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_MESSAGE
                and field.message_type.full_name == 'google.protobuf.Value'):
              sub_message = getattr(message, field.name)
              sub_message.null_value = 0
            elif (field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_ENUM
                  and field.enum_type.full_name == 'google.protobuf.NullValue'):
              setattr(message, field.name, 0)
            else:
              message.ClearField(field.name)
            continue
    
          # Parse field value.
          if _IsMapEntry(field):
            message.ClearField(field.name)
            self._ConvertMapFieldValue(value, message, field)
          elif field.label == descriptor.FieldDescriptor.LABEL_REPEATED:
>           message.ClearField(field.name)
E           TypeError: descriptor 'ClearField' for 'google.protobuf.pyext._message.CMessage' objects doesn't apply to a 'str' object

C:\installs\anaconda\envs\eunrg_elexeon_protobufs\lib\site-packages\google\protobuf\json_format.py:561: TypeError

During handling of the above exception, another exception occurred:

    def test3():
        msg0=MsgGrpType.MsgType(subject="test_subject0")
        msg1=MsgGrpType.MsgType(subject="test_subject1")
        msg2=MsgGrpType.MsgType(subject="test_subject3")
        msgGrp = MsgGrpType(flow="BOALF", msg=[msg0,msg1,msg2], pub_ts=datetime.datetime.now().isoformat())
    
        msgDict = google.protobuf.json_format.MessageToDict(msgGrp)
        pprint.pprint(msgDict)
>       result = ParseDict(msgDict, MsgGrpType, ignore_unknown_fields=True) # Crashes

test_boalf.py:52: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
C:\installs\anaconda\envs\eunrg_elexeon_protobufs\lib\site-packages\google\protobuf\json_format.py:454: in ParseDict
    parser.ConvertMessage(js_dict, message)
C:\installs\anaconda\envs\eunrg_elexeon_protobufs\lib\site-packages\google\protobuf\json_format.py:485: in ConvertMessage
    self._ConvertFieldValuePair(value, message)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = <google.protobuf.json_format._Parser object at 0x0000020177A3F2E0>
js = {'flow': 'BOALF', 'msg': [{'subject': 'test_subject0'}, {'subject': 'test_subject1'}, {'subject': 'test_subject3'}], 'pubTs': '2021-07-19T13:18:40.263824'}
message = <class 'com_elexeon_boalf_pb2.MsgGrpType'>

    def _ConvertFieldValuePair(self, js, message):
      """Convert field value pairs into regular message.
    
      Args:
        js: A JSON object to convert the field value pairs.
        message: A regular protocol message to record the data.
    
      Raises:
        ParseError: In case of problems converting.
      """
      names = []
      message_descriptor = message.DESCRIPTOR
      fields_by_json_name = dict((f.json_name, f)
                                 for f in message_descriptor.fields)
      for name in js:
        try:
          field = fields_by_json_name.get(name, None)
          if not field:
            field = message_descriptor.fields_by_name.get(name, None)
          if not field and _VALID_EXTENSION_NAME.match(name):
            if not message_descriptor.is_extendable:
              raise ParseError('Message type {0} does not have extensions'.format(
                  message_descriptor.full_name))
            identifier = name[1:-1]  # strip [] brackets
            # pylint: disable=protected-access
            field = message.Extensions._FindExtensionByName(identifier)
            # pylint: enable=protected-access
            if not field:
              # Try looking for extension by the message type name, dropping the
              # field name following the final . separator in full_name.
              identifier = '.'.join(identifier.split('.')[:-1])
              # pylint: disable=protected-access
              field = message.Extensions._FindExtensionByName(identifier)
              # pylint: enable=protected-access
          if not field:
            if self.ignore_unknown_fields:
              continue
            raise ParseError(
                ('Message type "{0}" has no field named "{1}".\n'
                 ' Available Fields(except extensions): {2}').format(
                     message_descriptor.full_name, name,
                     [f.json_name for f in message_descriptor.fields]))
          if name in names:
            raise ParseError('Message type "{0}" should not have multiple '
                             '"{1}" fields.'.format(
                                 message.DESCRIPTOR.full_name, name))
          names.append(name)
          value = js[name]
          # Check no other oneof field is parsed.
          if field.containing_oneof is not None and value is not None:
            oneof_name = field.containing_oneof.name
            if oneof_name in names:
              raise ParseError('Message type "{0}" should not have multiple '
                               '"{1}" oneof fields.'.format(
                                   message.DESCRIPTOR.full_name, oneof_name))
            names.append(oneof_name)
    
          if value is None:
            if (field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_MESSAGE
                and field.message_type.full_name == 'google.protobuf.Value'):
              sub_message = getattr(message, field.name)
              sub_message.null_value = 0
            elif (field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_ENUM
                  and field.enum_type.full_name == 'google.protobuf.NullValue'):
              setattr(message, field.name, 0)
            else:
              message.ClearField(field.name)
            continue
    
          # Parse field value.
          if _IsMapEntry(field):
            message.ClearField(field.name)
            self._ConvertMapFieldValue(value, message, field)
          elif field.label == descriptor.FieldDescriptor.LABEL_REPEATED:
            message.ClearField(field.name)
            if not isinstance(value, list):
              raise ParseError('repeated field {0} must be in [] which is '
                               '{1}.'.format(name, value))
            if field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_MESSAGE:
              # Repeated message field.
              for item in value:
                sub_message = getattr(message, field.name).add()
                # None is a null_value in Value.
                if (item is None and
                    sub_message.DESCRIPTOR.full_name != 'google.protobuf.Value'):
                  raise ParseError('null is not allowed to be used as an element'
                                   ' in a repeated field.')
                self.ConvertMessage(item, sub_message)
            else:
              # Repeated scalar field.
              for item in value:
                if item is None:
                  raise ParseError('null is not allowed to be used as an element'
                                   ' in a repeated field.')
                getattr(message, field.name).append(
                    _ConvertScalarFieldValue(item, field))
          elif field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_MESSAGE:
            if field.is_extension:
              sub_message = message.Extensions[field]
            else:
              sub_message = getattr(message, field.name)
            sub_message.SetInParent()
            self.ConvertMessage(value, sub_message)
          else:
            if field.is_extension:
              message.Extensions[field] = _ConvertScalarFieldValue(value, field)
            else:
              setattr(message, field.name, _ConvertScalarFieldValue(value, field))
        except ParseError as e:
          if field and field.containing_oneof is None:
            raise ParseError('Failed to parse {0} field: {1}.'.format(name, e))
          else:
            raise ParseError(str(e))
        except ValueError as e:
          raise ParseError('Failed to parse {0} field: {1}.'.format(name, e))
        except TypeError as e:
>         raise ParseError('Failed to parse {0} field: {1}.'.format(name, e))
E         google.protobuf.json_format.ParseError: Failed to parse msg field: descriptor 'ClearField' for 'google.protobuf.pyext._message.CMessage' objects doesn't apply to a 'str' object.

// com_elexeon_boalf.proto at 0:0
syntax = "proto3";
package com.elexeon.boalf;

message MsgGrpType {
  string pub_ts = 1;
  string flow = 2;
  repeated MsgType msg = 3;

  message MsgType {
    string subject = 1;
    int32 n_k = 2;
    string s_o = 3;
    string p_f = 4;
    string t_a = 5;
    string a_d = 6;
    int32 n_p = 7;
    repeated RowType row = 8;

    message RowType {
      string t_s = 1;
      double v_a = 2;
    }
  }
}