Consistency

[encukou]

All new API should strictly follow guidelines that we figure out in this repo -- not returning borrowed references, consistent signaling of errors, etc.

Any exceptions should only be added as alternatives to the above, and should be clearly identifiable from their names.

[gvanrossum]

Any exceptions should only be added as alternatives to the above, and should be clearly identifiable from their names.

Unless the API function exists for the express purpose of transferring ownership. (Which should still be documented, of course, but there may not be a version of the API that does not steal the reference. Canonical example being DECREF.)