import unittest
class Empty:
def __repr__(self):
return '<Empty>'
class Cmp:
def __init__(self,arg):
self.arg = arg
def __repr__(self):
return '<Cmp %s>' % self.arg
def __eq__(self, other):
return self.arg == other
class Anything:
def __eq__(self, other):
return True
def __ne__(self, other):
return False
class ComparisonTest(unittest.TestCase):
set1 = [2, 2.0, 2, 2+0j, Cmp(2.0)]
set2 = [[1], (3,), None, Empty()]
candidates = set1 + set2
def test_comparisons(self):
for a in self.candidates:
for b in self.candidates:
if ((a in self.set1) and (b in self.set1)) or a is b:
self.assertEqual(a, b)
else:
self.assertNotEqual(a, b)
def test_id_comparisons(self):
# Ensure default comparison compares id() of args
L = []
for i in range(10):
L.insert(len(L)//2, Empty())
for a in L:
for b in L:
self.assertEqual(a == b, id(a) == id(b),
'a=%r, b=%r' % (a, b))
def test_ne_defaults_to_not_eq(self):
a = Cmp(1)
b = Cmp(1)
c = Cmp(2)
self.assertIs(a == b, True)
self.assertIs(a != b, False)
self.assertIs(a != c, True)
def test_ne_high_priority(self):
"""object.__ne__() should allow reflected __ne__() to be tried"""
calls = []
class Left:
# Inherits object.__ne__()
def __eq__(*args):
calls.append('Left.__eq__')
return NotImplemented
class Right:
def __eq__(*args):
calls.append('Right.__eq__')
return NotImplemented
def __ne__(*args):
calls.append('Right.__ne__')
return NotImplemented
Left() != Right()
self.assertSequenceEqual(calls, ['Left.__eq__', 'Right.__ne__'])
def test_ne_low_priority(self):
"""object.__ne__() should not invoke reflected __eq__()"""
calls = []
class Base:
# Inherits object.__ne__()
def __eq__(*args):
calls.append('Base.__eq__')
return NotImplemented
class Derived(Base): # Subclassing forces higher priority
def __eq__(*args):
calls.append('Derived.__eq__')
return NotImplemented
def __ne__(*args):
calls.append('Derived.__ne__')
return NotImplemented
Base() != Derived()
self.assertSequenceEqual(calls, ['Derived.__ne__', 'Base.__eq__'])
def test_other_delegation(self):
"""No default delegation between operations except __ne__()"""
ops = (
('__eq__', lambda a, b: a == b),
('__lt__', lambda a, b: a < b),
('__le__', lambda a, b: a <= b),
('__gt__', lambda a, b: a > b),
('__ge__', lambda a, b: a >= b),
)
for name, func in ops:
with self.subTest(name):
def unexpected(*args):
self.fail('Unexpected operator method called')
class C:
__ne__ = unexpected
for other, _ in ops:
if other != name:
setattr(C, other, unexpected)
if name == '__eq__':
self.assertIs(func(C(), object()), False)
else:
self.assertRaises(TypeError, func, C(), object())
def test_issue_1393(self):
x = lambda: None
self.assertEqual(x, Anything())
self.assertEqual(Anything(), x)
y = object()
self.assertEqual(y, Anything())
self.assertEqual(Anything(), y)
if __name__ == '__main__':
unittest.main()