This behavior might be justifiable - if it were included in the docs. If you want to reduce resource consumption, you could zip the results, or deduplicate the

This behavior might be justifiable - if it were included in the docs. If you want to reduce resource consumption, you could zip the results, or deduplicate the values using a separate dict. There’s nothing unPythonic about a function returning mutable values. A common use for caching is wrapping a call to a remote servicer. If the response is JSON, it’s likely to be mutable. Nothing weird or edgy about that.