typing.get_origin behaves differently between standard collections and typing collections

Bug report

typing.get_origin behaves differently between standard collections, and typing collections
more specifically

get_origin(dict) is None, while get_origin(Dict) is <class 'dict'>
the same holds for other collections as well

This is true from python3.9 where support for standard collections was added

to my understanding dict should be able to be a drop-in replacement for Dict, which is not true in case relying on get_origin

I suggest updating get_origin to return the relevant class for builtin collections as opposed to None which returns today

note, this might mean a breaking change, as pointed out here, but id does make Dict and dict behave more similarly

まず、レポートで説明されている dict、Dict、およびその他のコレクションの組み合わせについて typing.get_origin を再現します。既存の get_origin の実装とそのテストを読み、その後、互換性を壊す変更のリスクについての議論を確認します。意図した動作について合意され、関連するコレクションのケースが一貫してカバーされれば完了です。