Synnefo » snf-ganeti

def UniqueFrozenset(seq):

  """Makes C{frozenset} from sequence after checking for duplicate elements.

  @raise ValueError: When there are duplicate elements

  """

  if isinstance(seq, (list, tuple)):

    items = seq

  else:

    items = list(seq)

  result = frozenset(items)

  if len(items) != len(result):

    raise ValueError("Duplicate values found")

  return result

class TestUniqueFrozenset(unittest.TestCase):

  def testDuplicates(self):

    for values in [["", ""], ["Hello", "World", "Hello"]]:

      self.assertRaises(ValueError, compat.UniqueFrozenset, values)

  def testEmpty(self):

    self.assertEqual(compat.UniqueFrozenset([]), frozenset([]))

  def testUnique(self):

    self.assertEqual(compat.UniqueFrozenset([1, 2, 3]), frozenset([1, 2, 3]))

  def testGenerator(self):

    seq = ("Foo%s" % i for i in range(10))

    self.assertTrue(callable(seq.next))

    self.assertFalse(isinstance(seq, (list, tuple)))

    self.assertEqual(compat.UniqueFrozenset(seq),

                     frozenset(["Foo%s" % i for i in range(10)]))