diff options
| -rw-r--r-- | Lib/heapq.py | 13 | ||||
| -rw-r--r-- | Misc/NEWS | 3 | ||||
| -rw-r--r-- | Modules/_heapqmodule.c | 40 |
3 files changed, 36 insertions, 20 deletions
diff --git a/Lib/heapq.py b/Lib/heapq.py index 4af9af1..0a83b76 100644 --- a/Lib/heapq.py +++ b/Lib/heapq.py @@ -167,7 +167,7 @@ def heapreplace(heap, item): def heappushpop(heap, item): """Fast version of a heappush followed by a heappop.""" - if heap and item > heap[0]: + if heap and heap[0] < item: item, heap[0] = heap[0], item _siftup(heap, 0) return item @@ -240,10 +240,11 @@ def _siftdown(heap, startpos, pos): while pos > startpos: parentpos = (pos - 1) >> 1 parent = heap[parentpos] - if parent <= newitem: - break - heap[pos] = parent - pos = parentpos + if newitem < parent: + heap[pos] = parent + pos = parentpos + continue + break heap[pos] = newitem # The child indices of heap index pos are already heaps, and we want to make @@ -294,7 +295,7 @@ def _siftup(heap, pos): while childpos < endpos: # Set childpos to index of smaller child. rightpos = childpos + 1 - if rightpos < endpos and heap[rightpos] <= heap[childpos]: + if rightpos < endpos and not heap[childpos] < heap[rightpos]: childpos = rightpos # Move the smaller child up. heap[pos] = heap[childpos] @@ -36,6 +36,9 @@ Core and Builtins Extension Modules ----------------- +- The heapq module does comparisons using LT instead of LE. This + makes its implementation match that used by list.sort(). + - Issue #2819: add full-precision summation function to math module, based on Hettinger's ASPN Python Cookbook recipe. diff --git a/Modules/_heapqmodule.c b/Modules/_heapqmodule.c index 1482b5a..ad2fd70 100644 --- a/Modules/_heapqmodule.c +++ b/Modules/_heapqmodule.c @@ -28,12 +28,12 @@ _siftdown(PyListObject *heap, Py_ssize_t startpos, Py_ssize_t pos) while (pos > startpos){ parentpos = (pos - 1) >> 1; parent = PyList_GET_ITEM(heap, parentpos); - cmp = PyObject_RichCompareBool(parent, newitem, Py_LE); + cmp = PyObject_RichCompareBool(newitem, parent, Py_LT); if (cmp == -1) { Py_DECREF(newitem); return -1; } - if (cmp == 1) + if (cmp == 0) break; Py_INCREF(parent); Py_DECREF(PyList_GET_ITEM(heap, pos)); @@ -69,14 +69,14 @@ _siftup(PyListObject *heap, Py_ssize_t pos) rightpos = childpos + 1; if (rightpos < endpos) { cmp = PyObject_RichCompareBool( - PyList_GET_ITEM(heap, rightpos), PyList_GET_ITEM(heap, childpos), - Py_LE); + PyList_GET_ITEM(heap, rightpos), + Py_LT); if (cmp == -1) { Py_DECREF(newitem); return -1; } - if (cmp == 1) + if (cmp == 0) childpos = rightpos; } /* Move the smaller child up. */ @@ -214,10 +214,10 @@ heappushpop(PyObject *self, PyObject *args) return item; } - cmp = PyObject_RichCompareBool(item, PyList_GET_ITEM(heap, 0), Py_LE); + cmp = PyObject_RichCompareBool(PyList_GET_ITEM(heap, 0), item, Py_LT); if (cmp == -1) return NULL; - if (cmp == 1) { + if (cmp == 0) { Py_INCREF(item); return item; } @@ -270,6 +270,7 @@ nlargest(PyObject *self, PyObject *args) { PyObject *heap=NULL, *elem, *iterable, *sol, *it, *oldelem; Py_ssize_t i, n; + int cmp; if (!PyArg_ParseTuple(args, "nO:nlargest", &n, &iterable)) return NULL; @@ -312,7 +313,12 @@ nlargest(PyObject *self, PyObject *args) else goto sortit; } - if (PyObject_RichCompareBool(elem, sol, Py_LE)) { + cmp = PyObject_RichCompareBool(sol, elem, Py_LT); + if (cmp == -1) { + Py_DECREF(elem); + goto fail; + } + if (cmp == 0) { Py_DECREF(elem); continue; } @@ -362,12 +368,12 @@ _siftdownmax(PyListObject *heap, Py_ssize_t startpos, Py_ssize_t pos) while (pos > startpos){ parentpos = (pos - 1) >> 1; parent = PyList_GET_ITEM(heap, parentpos); - cmp = PyObject_RichCompareBool(newitem, parent, Py_LE); + cmp = PyObject_RichCompareBool(parent, newitem, Py_LT); if (cmp == -1) { Py_DECREF(newitem); return -1; } - if (cmp == 1) + if (cmp == 0) break; Py_INCREF(parent); Py_DECREF(PyList_GET_ITEM(heap, pos)); @@ -403,14 +409,14 @@ _siftupmax(PyListObject *heap, Py_ssize_t pos) rightpos = childpos + 1; if (rightpos < endpos) { cmp = PyObject_RichCompareBool( - PyList_GET_ITEM(heap, childpos), PyList_GET_ITEM(heap, rightpos), - Py_LE); + PyList_GET_ITEM(heap, childpos), + Py_LT); if (cmp == -1) { Py_DECREF(newitem); return -1; } - if (cmp == 1) + if (cmp == 0) childpos = rightpos; } /* Move the smaller child up. */ @@ -434,6 +440,7 @@ nsmallest(PyObject *self, PyObject *args) { PyObject *heap=NULL, *elem, *iterable, *los, *it, *oldelem; Py_ssize_t i, n; + int cmp; if (!PyArg_ParseTuple(args, "nO:nsmallest", &n, &iterable)) return NULL; @@ -477,7 +484,12 @@ nsmallest(PyObject *self, PyObject *args) else goto sortit; } - if (PyObject_RichCompareBool(los, elem, Py_LE)) { + cmp = PyObject_RichCompareBool(elem, los, Py_LT); + if (cmp == -1) { + Py_DECREF(elem); + goto fail; + } + if (cmp == 0) { Py_DECREF(elem); continue; } |