[Python-Dev] Re: heapq API

[Scott David Daniels]

 > Josiah Carlson wrote:
 > Scott David Daniels wrote:
 >> Raymond Hettinger wrote:
 >>>    if not heap or item < heap[0]:
 >>>         return item
 >>>     return heapreplace(heap, item)
 >> Better is:
 >>       if heap and heap[0] < item:
 >>           return heapreplace(heap, item)
 >>       return item
 > The or method short-circuits too....

Sorry, I was (inadvertently) being cryptic:

I was avoiding the heapreplace call if item == heap[0].
Since "<" is the native ordering comparison, I reordered
the comparison to continue using "<".

While I was rearranging I dropped the "not" which was
probably a useless micro-optimization, but I usually
avoid not for clarity for myself these days.  I wouldn't
presume to correct just to fiddle out the not.

For the list, I'd probably have done better simply to write:
 > ...
 > Better is:
 >    if not heap or item <= heap[0]:
 >         return item
 >    return heapreplace(heap, item)
 > because you want to avoid calling heapreplace if possible.

-- 
-Scott David Daniels
Scott.Daniels at Acm.Org