Add Dataset, Model asset subclasses

[Lee-W]

Close: #42312

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[uranusjr]

Talked to Constance earlier; we should probably still make from airflow.datasets import Dataset work (and maybe also from airflow import Dataset). Without jumping through too many hoops, let’s just create a mostly empty airflow/datasets.py that emits a deprecation warning on import, and add a lazy import entry in airflow/__init__.py. Similar to how we handle name deprecations in providers.

Same for DatasetAlias; this one is not as important (I doubt many people are already using it aside from Cosmos), but we might as well add it since the mechanism is the same.

Those names should be removed in Airflow 3.2.

[Lee-W]

Talked to Constance earlier; we should probably still make from airflow.datasets import Dataset work (and maybe also from airflow import Dataset). Without jumping through too many hoops, let’s just create a mostly empty airflow/datasets.py that emits a deprecation warning on import, and add a lazy import entry in airflow/__init__.py. Similar to how we handle name deprecations in providers.

Same for DatasetAlias; this one is not as important (I doubt many people are already using it aside from Cosmos), but we might as well add it since the mechanism is the same.

Those names should be removed in Airflow 3.2.

Sounds good. Will do

[Lee-W]

Talked to Constance earlier; we should probably still make from airflow.datasets import Dataset work (and maybe also from airflow import Dataset). Without jumping through too many hoops, let’s just create a mostly empty airflow/datasets.py that emits a deprecation warning on import, and add a lazy import entry in airflow/__init__.py. Similar to how we handle name deprecations in providers.

Same for DatasetAlias; this one is not as important (I doubt many people are already using it aside from Cosmos), but we might as well add it since the mechanism is the same.

Those names should be removed in Airflow 3.2.

Updated