Patch #1549 by Thomas Herve.
This changes the rules for when __hash__ is inherited slightly,
by allowing it to be inherited when one or more of __lt__, __le__,
__gt__, __ge__ are overridden, as long as __eq__ and __ne__ aren't.
diff --git a/Lib/test/test_richcmp.py b/Lib/test/test_richcmp.py
index f412a89..db6d31f 100644
--- a/Lib/test/test_richcmp.py
+++ b/Lib/test/test_richcmp.py
@@ -85,6 +85,35 @@
raise ValueError, "Cannot compare vectors of different length"
return other
+
+class SimpleOrder(object):
+ """
+ A simple class that defines order but not full comparison.
+ """
+
+ def __init__(self, value):
+ self.value = value
+
+ def __lt__(self, other):
+ if not isinstance(other, SimpleOrder):
+ return True
+ return self.value < other.value
+
+ def __gt__(self, other):
+ if not isinstance(other, SimpleOrder):
+ return False
+ return self.value > other.value
+
+
+class DumbEqualityWithoutHash(object):
+ """
+ A class that define __eq__, but no __hash__: it shouldn't be hashable.
+ """
+
+ def __eq__(self, other):
+ return False
+
+
opmap = {
"lt": (lambda a,b: a< b, operator.lt, operator.__lt__),
"le": (lambda a,b: a<=b, operator.le, operator.__le__),
@@ -330,8 +359,39 @@
for op in opmap["lt"]:
self.assertIs(op(x, y), True)
+
+class HashableTest(unittest.TestCase):
+ """
+ Test hashability of classes with rich operators defined.
+ """
+
+ def test_simpleOrderHashable(self):
+ """
+ A class that only defines __gt__ and/or __lt__ should be hashable.
+ """
+ a = SimpleOrder(1)
+ b = SimpleOrder(2)
+ self.assert_(a < b)
+ self.assert_(b > a)
+ self.assert_(a.__hash__ is not None)
+
+ def test_notHashableException(self):
+ """
+ If a class is not hashable, it should raise a TypeError with an
+ understandable message.
+ """
+ a = DumbEqualityWithoutHash()
+ try:
+ hash(a)
+ except TypeError, e:
+ self.assertEquals(str(e),
+ "unhashable type: 'DumbEqualityWithoutHash'")
+ else:
+ raise test_support.TestFailed("Should not be here")
+
+
def test_main():
- test_support.run_unittest(VectorTest, NumberTest, MiscTest, DictTest, ListTest)
+ test_support.run_unittest(VectorTest, NumberTest, MiscTest, DictTest, ListTest, HashableTest)
if __name__ == "__main__":
test_main()