Lib/test/test_enumerate.py

   1 import unittest
   2
   3 from test import test_support
   4
   5 seq, res = 'abc', [(0,'a'), (1,'b'), (2,'c')]
   6
   7 class G:
   8     'Sequence using __getitem__'
   9     def __init__(self, seqn):
  10         self.seqn = seqn
  11     def __getitem__(self, i):
  12         return self.seqn[i]
  13
  14 class I:
  15     'Sequence using iterator protocol'
  16     def __init__(self, seqn):
  17         self.seqn = seqn
  18         self.i = 0
  19     def __iter__(self):
  20         return self
  21     def next(self):
  22         if self.i >= len(self.seqn): raise StopIteration
  23         v = self.seqn[self.i]
  24         self.i += 1
  25         return v
  26
  27 class Ig:
  28     'Sequence using iterator protocol defined with a generator'
  29     def __init__(self, seqn):
  30         self.seqn = seqn
  31         self.i = 0
  32     def __iter__(self):
  33         for val in self.seqn:
  34             yield val
  35
  36 class X:
  37     'Missing __getitem__ and __iter__'
  38     def __init__(self, seqn):
  39         self.seqn = seqn
  40         self.i = 0
  41     def next(self):
  42         if self.i >= len(self.seqn): raise StopIteration
  43         v = self.seqn[self.i]
  44         self.i += 1
  45         return v
  46
  47 class E:
  48     'Test propagation of exceptions'
  49     def __init__(self, seqn):
  50         self.seqn = seqn
  51         self.i = 0
  52     def __iter__(self):
  53         return self
  54     def next(self):
  55         3/0
  56
  57 class N:
  58     'Iterator missing next()'
  59     def __init__(self, seqn):
  60         self.seqn = seqn
  61         self.i = 0
  62     def __iter__(self):
  63         return self
  64
  65 class EnumerateTestCase(unittest.TestCase):
  66
  67     enum = enumerate
  68
  69     def test_basicfunction(self):
  70         self.assertEqual(type(self.enum(seq)), self.enum)
  71         e = self.enum(seq)
  72         self.assertEqual(iter(e), e)
  73         self.assertEqual(list(self.enum(seq)), res)
  74         self.enum.__doc__
  75
  76     def test_getitemseqn(self):
  77         self.assertEqual(list(self.enum(G(seq))), res)
  78         e = self.enum(G(''))
  79         self.assertRaises(StopIteration, e.next)
  80
  81     def test_iteratorseqn(self):
  82         self.assertEqual(list(self.enum(I(seq))), res)
  83         e = self.enum(I(''))
  84         self.assertRaises(StopIteration, e.next)
  85
  86     def test_iteratorgenerator(self):
  87         self.assertEqual(list(self.enum(Ig(seq))), res)
  88         e = self.enum(Ig(''))
  89         self.assertRaises(StopIteration, e.next)
  90
  91     def test_noniterable(self):
  92         self.assertRaises(TypeError, self.enum, X(seq))
  93
  94     def test_illformediterable(self):
  95         self.assertRaises(TypeError, list, self.enum(N(seq)))
  96
  97     def test_exception_propagation(self):
  98         self.assertRaises(ZeroDivisionError, list, self.enum(E(seq)))
  99
 100 class MyEnum(enumerate):
 101     pass
 102
 103 class SubclassTestCase(EnumerateTestCase):
 104
 105     enum = MyEnum
 106
 107 def suite():
 108     suite = unittest.TestSuite()
 109     suite.addTest(unittest.makeSuite(EnumerateTestCase))
 110     suite.addTest(unittest.makeSuite(SubclassTestCase))
 111     return suite
 112
 113 def test_main():
 114     test_support.run_suite(suite())
 115
 116 if __name__ == "__main__":
 117     test_main()