dogpile.cache.api defines KeyType: str
https://github.com/sqlalchemy/dogpile.cache/blob/main/dogpile/cache/api.py#L44-L45

Redis offers a hash/dict mapping for storage, which is accessible using the .hmget/.hmset methods from redis-py. The current backends do not support this, but third-party/developer backends and proxies do.

I'm not sure of the best way to support this for developers and potential future usage. The only thing i can think of is to extend KeyType to Union[str, Tuple[str]].