[Python-checkins] r79755 - in python/trunk: Doc/library/functions.rst Doc/library/functools.rst Doc/library/stdtypes.rst Lib/functools.py Lib/pstats.py Lib/test/test_functools.py Lib/unittest/loader.py Misc/NEWS
raymond.hettinger
python-checkins at python.org
Sun Apr 4 23:45:01 CEST 2010
Author: raymond.hettinger
Date: Sun Apr 4 23:45:01 2010
New Revision: 79755
Log:
Add tests for cmp_to_key.
Adopt PEP 8 compliant function name.
Factor-out existing uses cmp_to_key.
Update documentation to use internal pointers instead of external resource.
Modified:
python/trunk/Doc/library/functions.rst
python/trunk/Doc/library/functools.rst
python/trunk/Doc/library/stdtypes.rst
python/trunk/Lib/functools.py
python/trunk/Lib/pstats.py
python/trunk/Lib/test/test_functools.py
python/trunk/Lib/unittest/loader.py
python/trunk/Misc/NEWS
Modified: python/trunk/Doc/library/functions.rst
==============================================================================
--- python/trunk/Doc/library/functions.rst (original)
+++ python/trunk/Doc/library/functions.rst Sun Apr 4 23:45:01 2010
@@ -1154,9 +1154,8 @@
In general, the *key* and *reverse* conversion processes are much faster
than specifying an equivalent *cmp* function. This is because *cmp* is
called multiple times for each list element while *key* and *reverse* touch
- each element only once. To convert an old-style *cmp* function to a *key*
- function, see the `CmpToKey recipe in the ASPN cookbook
- <http://code.activestate.com/recipes/576653/>`_\.
+ each element only once. Use :func:`functools.cmp_to_key` to convert an
+ old-style *cmp* function to a *key* function.
For sorting examples and a brief sorting tutorial, see `Sorting HowTo
<http://wiki.python.org/moin/HowTo/Sorting/>`_\.
Modified: python/trunk/Doc/library/functools.rst
==============================================================================
--- python/trunk/Doc/library/functools.rst (original)
+++ python/trunk/Doc/library/functools.rst Sun Apr 4 23:45:01 2010
@@ -17,7 +17,7 @@
The :mod:`functools` module defines the following functions:
-.. function:: CmpToKey(func)
+.. function:: cmp_to_key(func)
Transform an old-style comparison function to a key-function. Used with
tools that accept key functions (such as :func:`sorted`, :func:`min`,
@@ -35,7 +35,7 @@
Example::
- sorted(iterable, key=CmpToKey(locale.strcoll)) # locale-aware sort order
+ sorted(iterable, key=cmp_to_key(locale.strcoll)) # locale-aware sort order
.. versionadded:: 2.7
Modified: python/trunk/Doc/library/stdtypes.rst
==============================================================================
--- python/trunk/Doc/library/stdtypes.rst (original)
+++ python/trunk/Doc/library/stdtypes.rst Sun Apr 4 23:45:01 2010
@@ -1618,7 +1618,8 @@
In general, the *key* and *reverse* conversion processes are much faster than
specifying an equivalent *cmp* function. This is because *cmp* is called
multiple times for each list element while *key* and *reverse* touch each
- element only once.
+ element only once. Use :func:`functools.cmp_to_key` to convert an
+ old-style *cmp* function to a *key* function.
.. versionchanged:: 2.3
Support for ``None`` as an equivalent to omitting *cmp* was added.
Modified: python/trunk/Lib/functools.py
==============================================================================
--- python/trunk/Lib/functools.py (original)
+++ python/trunk/Lib/functools.py Sun Apr 4 23:45:01 2010
@@ -76,7 +76,7 @@
setattr(cls, opname, opfunc)
return cls
-def CmpToKey(mycmp):
+def cmp_to_key(mycmp):
'Convert a cmp= function into a key= function'
class K(object):
def __init__(self, obj, *args):
Modified: python/trunk/Lib/pstats.py
==============================================================================
--- python/trunk/Lib/pstats.py (original)
+++ python/trunk/Lib/pstats.py Sun Apr 4 23:45:01 2010
@@ -37,6 +37,7 @@
import time
import marshal
import re
+from functools import cmp_to_key
__all__ = ["Stats"]
@@ -238,7 +239,7 @@
stats_list.append((cc, nc, tt, ct) + func +
(func_std_string(func), func))
- stats_list.sort(key=CmpToKey(TupleComp(sort_tuple).compare))
+ stats_list.sort(key=cmp_to_key(TupleComp(sort_tuple).compare))
self.fcn_list = fcn_list = []
for tuple in stats_list:
@@ -471,16 +472,6 @@
return direction
return 0
-def CmpToKey(mycmp):
- """Convert a cmp= function into a key= function"""
- class K(object):
- def __init__(self, obj):
- self.obj = obj
- def __lt__(self, other):
- return mycmp(self.obj, other.obj) == -1
- return K
-
-
#**************************************************************************
# func_name is a triple (file:string, line:int, name:string)
Modified: python/trunk/Lib/test/test_functools.py
==============================================================================
--- python/trunk/Lib/test/test_functools.py (original)
+++ python/trunk/Lib/test/test_functools.py Sun Apr 4 23:45:01 2010
@@ -338,7 +338,12 @@
self.assertEqual(reduce(42, "", "1"), "1") # func is never called with one item
self.assertRaises(TypeError, reduce, 42, (42, 42))
-
+class TestCmpToKey(unittest.TestCase):
+ def test_cmp_to_key(self):
+ def mycmp(x, y):
+ return y - x
+ self.assertEqual(sorted(range(5), key=functools.cmp_to_key(mycmp)),
+ [4, 3, 2, 1, 0])
def test_main(verbose=None):
Modified: python/trunk/Lib/unittest/loader.py
==============================================================================
--- python/trunk/Lib/unittest/loader.py (original)
+++ python/trunk/Lib/unittest/loader.py Sun Apr 4 23:45:01 2010
@@ -6,23 +6,13 @@
import traceback
import types
+from functools import cmp_to_key as _CmpToKey
from fnmatch import fnmatch
from . import case, suite
__unittest = True
-
-def _CmpToKey(mycmp):
- 'Convert a cmp= function into a key= function'
- class K(object):
- def __init__(self, obj):
- self.obj = obj
- def __lt__(self, other):
- return mycmp(self.obj, other.obj) == -1
- return K
-
-
# what about .pyc or .pyo (etc)
# we would need to avoid loading the same tests multiple times
# from '.py', '.pyc' *and* '.pyo'
Modified: python/trunk/Misc/NEWS
==============================================================================
--- python/trunk/Misc/NEWS (original)
+++ python/trunk/Misc/NEWS Sun Apr 4 23:45:01 2010
@@ -60,7 +60,7 @@
- the functools module now has a total_ordering() class decorator
to simplify the specifying rich comparisons.
-- The functools module also adds CmpToKey() as a tool to transition
+- The functools module also adds cmp_to_key() as a tool to transition
old-style comparison functions to new-style key-functions.
- Issue #8294: The Fraction constructor now accepts Decimal and float
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