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			83 lines
		
	
	
	
		
			2.7 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			83 lines
		
	
	
	
		
			2.7 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
| import unittest
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| from test import test_support, seq_tests
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| 
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| class TupleTest(seq_tests.CommonTest):
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|     type2test = tuple
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| 
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|     def test_constructors(self):
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|         super(TupleTest, self).test_len()
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|         # calling built-in types without argument must return empty
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|         self.assertEqual(tuple(), ())
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| 
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|     def test_truth(self):
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|         super(TupleTest, self).test_truth()
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|         self.assert_(not ())
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|         self.assert_((42, ))
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| 
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|     def test_len(self):
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|         super(TupleTest, self).test_len()
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|         self.assertEqual(len(()), 0)
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|         self.assertEqual(len((0,)), 1)
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|         self.assertEqual(len((0, 1, 2)), 3)
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| 
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|     def test_iadd(self):
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|         super(TupleTest, self).test_iadd()
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|         u = (0, 1)
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|         u2 = u
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|         u += (2, 3)
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|         self.assert_(u is not u2)
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| 
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|     def test_imul(self):
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|         super(TupleTest, self).test_imul()
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|         u = (0, 1)
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|         u2 = u
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|         u *= 3
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|         self.assert_(u is not u2)
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| 
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|     def test_tupleresizebug(self):
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|         # Check that a specific bug in _PyTuple_Resize() is squashed.
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|         def f():
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|             for i in range(1000):
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|                 yield i
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|         self.assertEqual(list(tuple(f())), range(1000))
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| 
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|     def test_hash(self):
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|         # See SF bug 942952:  Weakness in tuple hash
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|         # The hash should:
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|         #      be non-commutative
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|         #      should spread-out closely spaced values
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|         #      should not exhibit cancellation in tuples like (x,(x,y))
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|         #      should be distinct from element hashes:  hash(x)!=hash((x,))
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|         # This test exercises those cases.
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|         # For a pure random hash and N=50, the expected number of occupied
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|         #      buckets when tossing 252,600 balls into 2**32 buckets
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|         #      is 252,592.6, or about 7.4 expected collisions.  The
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|         #      standard deviation is 2.73.  On a box with 64-bit hash
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|         #      codes, no collisions are expected.  Here we accept no
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|         #      more than 15 collisions.  Any worse and the hash function
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|         #      is sorely suspect.
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| 
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|         N=50
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|         base = range(N)
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|         xp = [(i, j) for i in base for j in base]
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|         inps = base + [(i, j) for i in base for j in xp] + \
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|                      [(i, j) for i in xp for j in base] + xp + zip(base)
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|         collisions = len(inps) - len(set(map(hash, inps)))
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|         self.assert_(collisions <= 15)
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| 
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|     def test_repr(self):
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|         l0 = tuple()
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|         l2 = (0, 1, 2)
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|         a0 = self.type2test(l0)
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|         a2 = self.type2test(l2)
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| 
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|         self.assertEqual(str(a0), repr(l0))
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|         self.assertEqual(str(a2), repr(l2))
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|         self.assertEqual(repr(a0), "()")
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|         self.assertEqual(repr(a2), "(0, 1, 2)")
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| 
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| def test_main():
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|     test_support.run_unittest(TupleTest)
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| 
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| if __name__=="__main__":
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|     test_main()
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