> So, as soon as (but only as soon as) you mix unicode with your non-ascii data, your program blows up.

Indeed. For context tho my example of running into this the unicode literals used as seperators weren't even in the same package as the non-ASCII binary strings. (JSONRenderer in Django REST framework, being excersized by some third party test code. End result non-obvious exception.

Anyways, okay with this resolution, although I am now using a compat branch to ensure that we use binary seperators in py2 to continue to get the more lax rendering style.