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| author | Raymond Hettinger <python@rcn.com> | 2007-01-04 17:53:34 (GMT) |
|---|---|---|
| committer | Raymond Hettinger <python@rcn.com> | 2007-01-04 17:53:34 (GMT) |
| commit | 769a40a1d046baddbac4c01fa8feada2ee9e5207 (patch) | |
| tree | ad7a34d423aeb39afb406b0427996012595369c8 /Lib/heapq.py | |
| parent | 2dc4db017483a25d9f2438ae4f36d98ec954ed37 (diff) | |
| download | cpython-769a40a1d046baddbac4c01fa8feada2ee9e5207.zip cpython-769a40a1d046baddbac4c01fa8feada2ee9e5207.tar.gz cpython-769a40a1d046baddbac4c01fa8feada2ee9e5207.tar.bz2 | |
Fix stability of heapq's nlargest() and nsmallest().
Diffstat (limited to 'Lib/heapq.py')
| -rw-r--r-- | Lib/heapq.py | 8 |
1 files changed, 2 insertions, 6 deletions
diff --git a/Lib/heapq.py b/Lib/heapq.py index 04725cd..753c3b7 100644 --- a/Lib/heapq.py +++ b/Lib/heapq.py @@ -130,7 +130,7 @@ __all__ = ['heappush', 'heappop', 'heapify', 'heapreplace', 'nlargest', 'nsmallest'] from itertools import islice, repeat, count, imap, izip, tee -from operator import itemgetter +from operator import itemgetter, neg import bisect def heappush(heap, item): @@ -315,8 +315,6 @@ def nsmallest(n, iterable, key=None): Equivalent to: sorted(iterable, key=key)[:n] """ - if key is None: - return _nsmallest(n, iterable) in1, in2 = tee(iterable) it = izip(imap(key, in1), count(), in2) # decorate result = _nsmallest(n, it) @@ -328,10 +326,8 @@ def nlargest(n, iterable, key=None): Equivalent to: sorted(iterable, key=key, reverse=True)[:n] """ - if key is None: - return _nlargest(n, iterable) in1, in2 = tee(iterable) - it = izip(imap(key, in1), count(), in2) # decorate + it = izip(imap(key, in1), imap(neg, count()), in2) # decorate result = _nlargest(n, it) return map(itemgetter(2), result) # undecorate |