dataclass needs to examine the annotations of class objects it decorates. Due to__annotations__ being badly designed, it currently pulls the__annotations__ out of the class dict (cls.__dict__.get('__annotations__')). While this works today, this wouldn't work properly for classes defiend in modules usingfrom __future__ import co_annotations if PEP 649 is accepted. It's also not recommended best practices for working with annotations. (Which, admittedly,I wrote.)

Best practices call for usinginspect.get_annotations to get the annotations on any object. This does exactly whatdataclass wants; it doesn't inherit base class annotations if no child class defines annotations, and it always returns a dict. (Empty, if appropriate.)

dataclass has in the past resisted usinginspect.get_annotations because it didn't want to incur the runtime cost of importinginspect. However, as of this time in CPython trunk,inspect is always imported during startup, anddataclass is already importing it anyway. It's timedataclass changed to best practices here.