Port r69838: Speedup and simplify negative counter using count's new step argument.

This commit is contained in:
Raymond Hettinger 2009-02-21 22:10:18 +00:00
parent 934896dc09
commit bd171bcfc4
1 changed files with 3 additions and 3 deletions

View File

@ -130,7 +130,7 @@ __all__ = ['heappush', 'heappop', 'heapify', 'heapreplace', 'merge',
'nlargest', 'nsmallest', 'heappushpop']
from itertools import islice, repeat, count, tee, chain
from operator import itemgetter, neg
from operator import itemgetter
import bisect
def heappush(heap, item):
@ -413,13 +413,13 @@ def nlargest(n, iterable, key=None):
# When key is none, use simpler decoration
if key is None:
it = zip(iterable, map(neg, count())) # decorate
it = zip(iterable, count(0,-1)) # decorate
result = _nlargest(n, it)
return list(map(itemgetter(0), result)) # undecorate
# General case, slowest method
in1, in2 = tee(iterable)
it = zip(map(key, in1), map(neg, count()), in2) # decorate
it = zip(map(key, in1), count(0,-1), in2) # decorate
result = _nlargest(n, it)
return list(map(itemgetter(2), result)) # undecorate