With the use_proto_plus configuration parameter, you can specify whether you
want the library to return
proto-plus messages or
protobuf messages. For details on
how to set this parameter, see the configuration docs.
This section describes the performance implications of choosing which types of messages to use, therefore, we recommend that you read and understand the options in order to make an informed decision.
Proto-plus versus protobuf messages
The code generator pipeline integrates proto-plus as a way to improve the ergonomics of the protobuf message interface by making them behave more like native Python objects. However, this means that using proto-plus introduces performance overhead.
Proto-plus performance
One of the core benefits of proto-plus is that it converts protobuf messages and well-known types to native Python types through a process called type marshaling.
Marshaling occurs when a field is accessed on a proto-plus message instance, specifically when a field is either read or set, for example, in a protobuf definition:
syntax = "proto3";
message Dog {
string name = 1;
}
When this definition is converted to a proto-plus class, it would look something like this:
import proto
class Dog(proto.Message):
name = proto.Field(proto.STRING, number=1)
You can then initialize the Dog class and access its name field as you would
any other Python object:
dog = Dog()
dog.name = "Scruffy"
print(dog.name)
When reading and setting the name field, the value is converted from a native
Python str type to a string type so
that the value is compatible with the protobuf runtime.
Based on our performance analyses, we have determined that the time spent doing these type conversions has a large enough performance impact that users should decide, based on their needs, whether or not to use protobuf messages.
Use cases for proto-plus and protobuf messages
- Proto-plus message use cases
- Proto-plus offers a number of ergonomic improvements over protobuf messages, so they're ideal for writing maintainable, readable code. Since they expose native Python objects, they're easier to use and understand.
- Protobuf message use cases
- Use protobufs for performance-sensitive use cases, specifically in apps
that need to process large reports quickly, or that build mutate requests with a
large number of operations, for example with
BatchJobServiceorOfflineUserDataJobService.
Dynamically changing message types
After selecting the appropriate message type for your app, you might find
that you need to use the other type for a specific workflow. In this case, it's
easy to switch between the two types dynamically using utilities offered by the
client library. Using the same Dog message class from above:
from google.ads.googleads import util
# Proto-plus message type
dog = Dog()
# Protobuf message type
dog = util.convert_proto_plus_to_protobuf(dog)
# Back to proto-plus message type
dog = util.convert_protobuf_to_proto_plus(dog)
Protobuf message interface differences
The proto-plus interface is documented in detail, but here we'll highlight some key differences that affect common use cases for the Google Ads client library.
Bytes serialization
- Proto-plus messages
serialized = type(campaign).serialize(campaign) deserialized = type(campaign).deserialize(serialized)
- Protobuf messages
serialized = campaign.SerializeToString() deserialized = campaign.FromString(serialized)
JSON serialization
- Proto-plus messages
serialized = type(campaign).to_json(campaign) deserialized = type(campaign).from_json(serialized)
- Protobuf messages
from google.protobuf.json_format import MessageToJson, Parse serialized = MessageToJson(campaign) deserialized = Parse(serialized, campaign)
Field masks
The field mask helper method provided by api-core is designed to use protobuf message instances. So when using proto-plus messages, convert them to protobuf messages to utilize the helper:
- Proto-plus messages
from google.api_core.protobuf_helpers import field_mask campaign = client.get_type("Campaign") protobuf_campaign = util.convert_proto_plus_to_protobuf(campaign) mask = field_mask(None, protobuf_campaign)
- Protobuf messages
from google.api_core.protobuf_helpers import field_mask campaign = client.get_type("Campaign") mask = field_mask(None, campaign)
Enums
Enums exposed by proto-plus messages are instances of Python's native
enum type and therefore
inherit a number of convenience methods.
Enum type retrieval
When using the GoogleAdsClient.get_type method to retrieve enums, the messages
that are returned are slightly different depending on whether you're using
proto-plus or protobuf messages. For example:
- Proto-plus messages
val = client.get_type("CampaignStatusEnum").CampaignStatus.PAUSED
- Protobuf messages
val = client.get_type("CampaignStatusEnum").PAUSED
To make retrieving enums simpler, there's a convenience attribute on
GoogleAdsClient instances that has a consistent interface regardless of which
message type you're using:
val = client.enums.CampaignStatusEnum.PAUSED
Enum value retrieval
Sometimes it's useful to know the value, or field ID, of a given enum, for
example, PAUSED on the CampaignStatusEnum corresponds to 3:
- Proto-plus messages
campaign = client.get_type("Campaign") campaign.status = client.enums.CampaignStatusEnum.PAUSED # To read the value of campaign status print(campaign.status.value)
- Protobuf messages
campaign = client.get_type("Campaign") status_enum = client.enums.CampaignStatusEnum campaign.status = status_enum.PAUSED # To read the value of campaign status print(status_enum.CampaignStatus.Value(campaign.status))
Enum name retrieval
Sometimes it's useful to know the name of an enum field. For example, when
reading objects from the API you might want to know which campaign status the
int 3 corresponds to:
- Proto-plus messages
campaign = client.get_type("Campaign") campaign.status = client.enums.CampaignStatusEnum.PAUSED # To read the name of campaign status print(campaign.status.name)
- Protobuf messages
campaign = client.get_type("Campaign") status_enum = client.enums.CampaignStatusEnum # Sets the campaign status to the int value for PAUSED campaign.status = status_enum.PAUSED # To read the name of campaign status status_enum.CampaignStatus.Name(campaign.status)
Repeated fields
As described in the proto-plus
docs,
repeated fields are generally equivalent to typed lists, which means that they
behave almost identically to a list.
Append values to repeated scalar fields
When adding values to repeated scalar
type fields, for example
string or int64 fields, the interface is the same regardless of message
type:
- Proto-plus messages
ad.final_urls.append("https://www.example.com")
- Protobuf messages
ad.final_urls.append("https://www.example.com")
This includes all other common list methods as well, for example extend:
- Proto-plus messages
ad.final_urls.extend(["https://www.example.com", "https://www.example.com/2"])
- Protobuf messages
ad.final_urls.extend(["https://www.example.com", "https://www.example.com/2"])
Append message types to repeated fields
If the repeated field is not a scalar type, the behavior when adding them to repeated fields is slightly different:
- Proto-plus messages
frequency_cap = client.get_type("FrequencyCapEntry") frequency_cap.cap = 100 campaign.frequency_caps.append(frequency_cap)
- Protobuf messages
# The add method initializes a message and adds it to the repeated field frequency_cap = campaign.frequency_caps.add() frequency_cap.cap = 100
Assign repeated fields
For both scalar and non-scalar repeated fields, you can assign lists to the field in different ways:
- Proto-plus messages
# In proto-plus it's possible to use assignment. urls = ["https://www.example.com"] ad.final_urls = urls
- Protobuf messages
# Protobuf messages do not allow assignment, but you can replace the # existing list using slice syntax. urls = ["https://www.example.com"] ad.final_urls[:] = urls
Empty messages
Sometimes it's useful to know whether a message instance contains any information, or has any of its fields set.
- Proto-plus messages
# When using proto-plus messages you can simply check the message for # truthiness. is_empty = bool(campaign) is_empty = not campaign
- Protobuf messages
is_empty = campaign.ByteSize() == 0
Message copy
For both proto-plus and protobuf messages, we recommend using the copy_from
helper method on the GoogleAdsClient:
client.copy_from(campaign, other_campaign)
Empty message fields
The process for setting empty message fields is the same regardless of the message type you're using. You just need to copy an empty message into the field in question. See the Message copy section as well as the Empty Message Fields guide. Here's an example of how to set an empty message field:
client.copy_from(campaign.manual_cpm, client.get_type("ManualCpm"))
Field names that are reserved words
When using proto-plus messages, field names automatically appear with a
trailing underscore if the name is also a reserved word in Python. Here's an
example of working with an Asset instance:
asset = client.get_type("Asset")
asset.type_ = client.enums.AssetTypeEnum.IMAGE
The full list of reserved names is constructed in the gapic generator module. It can be accessed programmatically as well.
First, install the module:
python -m pip install gapic-generator
Then, in a Python REPL or script:
import gapic.utils
print(gapic.utils.reserved_names.RESERVED_NAMES)
Field presence
Because the fields on protobuf message instances have default values, it's not always intuitive to know whether a field has been set or not.
- Proto-plus messages
# Use the "in" operator. has_field = "name" in campaign
- Protobuf messages
campaign = client.get_type("Campaign") # Determines whether "name" is set and not just an empty string. campaign.HasField("name")
The protobuf
Message
class interface has a HasField method that determines whether the field on a
message has been set, even if it was set to a default value.
Protobuf message methods
The protobuf message interface includes some convenience methods that are not part of the proto-plus interface; however, it's simple to access them by converting a proto-plus message to its protobuf counterpart:
# Accessing the ListFields method
protobuf_campaign = util.convert_protobuf_to_proto_plus(campaign)
print(campaign.ListFields())
# Accessing the Clear method
protobuf_campaign = util.convert_protobuf_to_proto_plus(campaign)
print(campaign.Clear())
Issue tracker
If you have any questions about these changes or any problems migrating to the latest version of the library, file an issue on our tracker.