[Python-Dev] PEP 0424: A method for exposing a length hint

Tue Jul 17 05:03:08 CEST 2012

I've updated the PEP to reflect the discussion. There are two major changes:
1) NotImplemented may be used by __length_hint__ to indicate that there is no 
 finite length hint available.
2) callers of operator.length_hint() must provide their own default value, this
 is also required by the current C _PyObject_LengthHint implementation.
There are no provisions for infinite iterators, that is not within the scope of
this proposal.
Alex