> The parallel API would have to be:
> 
> json.dump_bytes
> json.dumps_bytes
> json.load_bytes
> json.loads_bytes

No, only one function dump_bytes() is needed, and it would return a
bytes object ("dumps" meaning "dump string", already). loads() can be
polymorphic without creating a new function.

I don't think the functions taking file objects are used often enough to
warrant a second API to deal with binary files.

> It doesn't need to be documented as a completely separate module, it can
> just be a subsection in the json module docs with a reference to the
> relevant RFC.

It's still completely weird and unusual.

> "Namespaces are a honking great idea; let's do more of those"

And also "flat is better than nested".

Especially when you're proposing than one API be at level N, and the
other, closely related API be at level N+1.