Issue #10042: Fixed the total_ordering decorator to handle cross-type
comparisons that could lead to infinite recursion.
diff --git a/Lib/functools.py b/Lib/functools.py
index d450634..1062a45 100644
--- a/Lib/functools.py
+++ b/Lib/functools.py
@@ -68,17 +68,17 @@
def total_ordering(cls):
"""Class decorator that fills in missing ordering methods"""
convert = {
- '__lt__': [('__gt__', lambda self, other: other < self),
- ('__le__', lambda self, other: not other < self),
+ '__lt__': [('__gt__', lambda self, other: not (self < other or self == other)),
+ ('__le__', lambda self, other: self < other or self == other),
('__ge__', lambda self, other: not self < other)],
- '__le__': [('__ge__', lambda self, other: other <= self),
- ('__lt__', lambda self, other: not other <= self),
+ '__le__': [('__ge__', lambda self, other: not self <= other or self == other),
+ ('__lt__', lambda self, other: self <= other and not self == other),
('__gt__', lambda self, other: not self <= other)],
- '__gt__': [('__lt__', lambda self, other: other > self),
- ('__ge__', lambda self, other: not other > self),
+ '__gt__': [('__lt__', lambda self, other: not (self > other or self == other)),
+ ('__ge__', lambda self, other: self > other or self == other),
('__le__', lambda self, other: not self > other)],
- '__ge__': [('__le__', lambda self, other: other >= self),
- ('__gt__', lambda self, other: not other >= self),
+ '__ge__': [('__le__', lambda self, other: (not self >= other) or self == other),
+ ('__gt__', lambda self, other: self >= other and not self == other),
('__lt__', lambda self, other: not self >= other)]
}
# Find user-defined comparisons (not those inherited from object).
diff --git a/Lib/test/test_functools.py b/Lib/test/test_functools.py
index f41a144..73a77d6 100644
--- a/Lib/test/test_functools.py
+++ b/Lib/test/test_functools.py
@@ -457,6 +457,8 @@
self.value = value
def __lt__(self, other):
return self.value < other.value
+ def __eq__(self, other):
+ return self.value == other.value
self.assertTrue(A(1) < A(2))
self.assertTrue(A(2) > A(1))
self.assertTrue(A(1) <= A(2))
@@ -471,6 +473,8 @@
self.value = value
def __le__(self, other):
return self.value <= other.value
+ def __eq__(self, other):
+ return self.value == other.value
self.assertTrue(A(1) < A(2))
self.assertTrue(A(2) > A(1))
self.assertTrue(A(1) <= A(2))
@@ -485,6 +489,8 @@
self.value = value
def __gt__(self, other):
return self.value > other.value
+ def __eq__(self, other):
+ return self.value == other.value
self.assertTrue(A(1) < A(2))
self.assertTrue(A(2) > A(1))
self.assertTrue(A(1) <= A(2))
@@ -499,6 +505,8 @@
self.value = value
def __ge__(self, other):
return self.value >= other.value
+ def __eq__(self, other):
+ return self.value == other.value
self.assertTrue(A(1) < A(2))
self.assertTrue(A(2) > A(1))
self.assertTrue(A(1) <= A(2))
@@ -524,6 +532,22 @@
class A:
pass
+ def test_bug_10042(self):
+ @functools.total_ordering
+ class TestTO:
+ def __init__(self, value):
+ self.value = value
+ def __eq__(self, other):
+ if isinstance(other, TestTO):
+ return self.value == other.value
+ return False
+ def __lt__(self, other):
+ if isinstance(other, TestTO):
+ return self.value < other.value
+ raise TypeError
+ with self.assertRaises(TypeError):
+ TestTO(8) <= ()
+
class TestLRU(unittest.TestCase):
def test_lru(self):