SF bug 693121: Set == non-Set is a TypeError.
Allow mixed-type __eq__ and __ne__ for Set objects. This is messier than
I'd like because Set *also* implements __cmp__. I know of one glitch now:
cmp(s, t) returns 0 now when s and t are both Sets and s == t, despite
that Set.__cmp__ unconditionally raises TypeError (and by intent). The
rub is that __eq__ gets tried first, and the x.__eq__(y) True result
convinces Python that cmp(x, y) is 0 without even calling Set.__cmp__.
diff --git a/Lib/test/test_sets.py b/Lib/test/test_sets.py
index 9223596..d8b7f3f 100644
--- a/Lib/test/test_sets.py
+++ b/Lib/test/test_sets.py
@@ -232,7 +232,16 @@
def test_cmp(self):
a, b = Set('a'), Set('b')
- self.assertRaises(TypeError, cmp, (a,b))
+ self.assertRaises(TypeError, cmp, a, b)
+
+ # You can view this as a buglet: cmp(a, a) does not raise TypeError,
+ # because __eq__ is tried before __cmp__, and a.__eq__(a) returns,
+ # which Python thinks is good enough to synthesize a cmp() result
+ # without calling __cmp__.
+ self.assertEqual(cmp(a, a), 0)
+
+ self.assertRaises(TypeError, cmp, a, 12)
+ self.assertRaises(TypeError, cmp, "abc", a)
#==============================================================================
@@ -476,17 +485,19 @@
class TestOnlySetsInBinaryOps(unittest.TestCase):
- def test_cmp(self):
- try:
- self.other == self.set
- self.fail("expected TypeError")
- except TypeError:
- pass
- try:
- self.set != self.other
- self.fail("expected TypeError")
- except TypeError:
- pass
+ def test_eq_ne(self):
+ # Unlike the others, this is testing that == and != *are* allowed.
+ self.assertEqual(self.other == self.set, False)
+ self.assertEqual(self.set == self.other, False)
+ self.assertEqual(self.other != self.set, True)
+ self.assertEqual(self.set != self.other, True)
+
+ def test_ge_gt_lt_le(self):
+ # Unlike the others, this is testing that == and != *are* allowed.
+ self.assertRaises(TypeError, lambda: self.set < self.other)
+ self.assertRaises(TypeError, lambda: self.set <= self.other)
+ self.assertRaises(TypeError, lambda: self.set > self.other)
+ self.assertRaises(TypeError, lambda: self.set >= self.other)
def test_union_update(self):
try: