In Py3.x, a list comprehension is now faster than list(map(itemgetter(0), iterable)).
diff --git a/Lib/heapq.py b/Lib/heapq.py
index b361631..19a457b 100644
--- a/Lib/heapq.py
+++ b/Lib/heapq.py
@@ -130,7 +130,6 @@
'nlargest', 'nsmallest', 'heappushpop']
from itertools import islice, repeat, count, tee, chain
-from operator import itemgetter
import bisect
def heappush(heap, item):
@@ -377,13 +376,13 @@
if key is None:
it = zip(iterable, count()) # decorate
result = _nsmallest(n, it)
- return list(map(itemgetter(0), result)) # undecorate
+ return [r[0] for r in result] # undecorate
# General case, slowest method
in1, in2 = tee(iterable)
it = zip(map(key, in1), count(), in2) # decorate
result = _nsmallest(n, it)
- return list(map(itemgetter(2), result)) # undecorate
+ return [r[2] for r in result] # undecorate
_nlargest = nlargest
def nlargest(n, iterable, key=None):
@@ -415,13 +414,13 @@
if key is None:
it = zip(iterable, count(0,-1)) # decorate
result = _nlargest(n, it)
- return list(map(itemgetter(0), result)) # undecorate
+ return [r[0] for r in result] # undecorate
# General case, slowest method
in1, in2 = tee(iterable)
it = zip(map(key, in1), count(0,-1), in2) # decorate
result = _nlargest(n, it)
- return list(map(itemgetter(2), result)) # undecorate
+ return [r[2] for r in result] # undecorate
if __name__ == "__main__":
# Simple sanity test