Idiomatic Python API

[rgov]

Has any thought been given to developing an idiomatic Python API for Fast DDS? The API requires a coding style that is fairly unnatural in Python.

Some examples:

Accessing instance variables on objects:

# not idiomatic
data.message()
self.topic_data_type.getName()

# idiomatic
data.message
self.topic_data_type.name

Setting instance variables on objects:

# not idiomatic
data.message("Hello World")
self.topic_data_type.setName("HelloWorld")  # p.s., why does this one use "set" and other doesn't?


# idiomatic
data.message = "Hello World"
self.topic_data_type.name = "HelloWorld"

Passing objects by reference to have them initialized:

# not idiomatic
info = fastdds.SampleInfo()
data = HelloWorld.HelloWorld()
reader.take_next_sample(data, info)

# idiomatic
data, info = reader.take_next_sample()


# not idiomatic
self.subscriber_qos = fastdds.SubscriberQos()
self.participant.get_default_subscriber_qos(self.subscriber_qos)

# idiomatic, kind of?
self.subscriber_qos = self.participant.create_subscriber_qos()
self.subscriber_qos = fastdds.SubscriberQos.create_from(self.participant)

Manual management of resources:

# not idiomatic
factory = fastdds.DomainParticipantFactory.get_instance()
self.participant.delete_contained_entities()
factory.delete_participant(self.participant)

# idiomatic, often happens implicitly
del self.participant

[rgov]

Presumably this is mostly a consequence of using SWIG to generate the Python bindings.

SWIG does have %attribute for wrapping setters and getters in an idiomatic way.

I've also heard decent things about pybind11. This example shows how to handle mapping Python object properties to C++ setters and getters like getName() and setName()

[JLBuenoLopez]

Thanks @rgov for your contribution

I have labeled this as an enhancement and I am moving the ticket to the Ideas discussion forum. For the moment the Python API will remain as it is.