[Python-ideas] Revised^4 PEP on yield-from

[Greg Ewing]

Raymond Hettinger wrote:

> The hasattr() tests can be expensive for repeated throwers and senders.
> Any merit to caching the result of the test?

The expansion is a specification of the semantics, not
an implementation.

My current implementation does something like

   _m = getattr(_i, 'throw', None)
   if _m:
     _m(_e)

and a further optimisation would be to cache the
bound method.

-- 
Greg