google.protobuf.message

Contains an abstract base class for protocol messages.

exception google.protobuf.message.DecodeError
args
with_traceback()

Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception google.protobuf.message.EncodeError
args
with_traceback()

Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception google.protobuf.message.Error
args
with_traceback()

Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

class google.protobuf.message.Message

Abstract base class for protocol messages.

Protocol message classes are almost always generated by the protocol compiler. These generated types subclass Message and implement the methods shown below.

TODO(robinson): Link to an HTML document here.

TODO(robinson): Document that instances of this class will also have an Extensions attribute with __getitem__ and __setitem__. Again, not sure how to best convey this.

TODO(robinson): Document that the class must also have a static

RegisterExtension(extension_field) method. Not sure how to best express at this point.

ByteSize()

Returns the serialized size of this message. Recursively calls ByteSize() on all contained messages.

Clear()

Clears all data that was set in the message.

ClearExtension(extension_handle)
ClearField(field_name)

Clears the contents of a given field, or the field set inside a oneof group. If the name neither refers to a defined field or oneof group, ValueError is raised.

CopyFrom(other_msg)

Copies the content of the specified message into the current message.

The method clears the current message and then merges the specified message using MergeFrom.

Parameters

other_msg – Message to copy into the current one.

DESCRIPTOR = None
DiscardUnknownFields()
HasExtension(extension_handle)
HasField(field_name)

Checks if a certain field is set for the message, or if any field inside a oneof group is set. Note that if the field_name is not defined in the message descriptor, ValueError will be raised.

IsInitialized()

Checks if the message is initialized.

Returns

The method returns True if the message is initialized (i.e. all of its required fields are set).

ListFields()

Returns a list of (FieldDescriptor, value) tuples for all fields in the message which are not empty. A message field is non-empty if HasField() would return true. A singular primitive field is non-empty if HasField() would return true in proto2 or it is non zero in proto3. A repeated field is non-empty if it contains at least one element. The fields are ordered by field number

MergeFrom(other_msg)

Merges the contents of the specified message into current message.

This method merges the contents of the specified message into the current message. Singular fields that are set in the specified message overwrite the corresponding fields in the current message. Repeated fields are appended. Singular sub-messages and groups are recursively merged.

Parameters

other_msg – Message to merge into the current message.

MergeFromString(serialized)

Merges serialized protocol buffer data into this message.

When we find a field in |serialized| that is already present in this message:

  • If it’s a “repeated” field, we append to the end of our list.

  • Else, if it’s a scalar, we overwrite our field.

  • Else, (it’s a nonrepeated composite), we recursively merge into the existing composite.

TODO(robinson): Document handling of unknown fields.

Parameters

serialized – Any object that allows us to call buffer(serialized) to access a string of bytes using the buffer interface.

TODO(robinson): When we switch to a helper, this will return None.

Returns

The number of bytes read from |serialized|. For non-group messages, this will always be len(serialized), but for messages which are actually groups, this will generally be less than len(serialized), since we must stop when we reach an END_GROUP tag. Note that if we do stop because of an END_GROUP tag, the number of bytes returned does not include the bytes for the END_GROUP tag information.

Raises

message.DecodeError if the input cannot be parsed.

ParseFromString(serialized)

Parse serialized protocol buffer data into this message.

Like MergeFromString(), except we clear the object first.

SerializePartialToString(**kwargs)

Serializes the protocol message to a binary string.

This method is similar to SerializeToString but doesn’t check if the message is initialized.

Parameters

**kwargs

Keyword arguments to the serialize method, accepts the following keyword args: deterministic: If true, requests deterministic serialization of the

protobuf, with predictable ordering of map keys.

Returns

A string representation of the partial message.

SerializeToString(**kwargs)

Serializes the protocol message to a binary string.

Parameters

**kwargs

Keyword arguments to the serialize method, accepts the following keyword args: deterministic: If true, requests deterministic serialization of the

protobuf, with predictable ordering of map keys.

Returns

A binary string representation of the message if all of the required fields in the message are set (i.e. the message is initialized).

Raises

message.EncodeError if the message isn't initialized.

SetInParent()

Mark this as present in the parent.

This normally happens automatically when you assign a field of a sub-message, but sometimes you want to make the sub-message present while keeping it empty. If you find yourself using this, you may want to reconsider your design.

UnknownFields()

Returns the UnknownFieldSet.

WhichOneof(oneof_group)

Returns the name of the field that is set inside a oneof group, or None if no field is set. If no group with the given name exists, ValueError will be raised.