Lib/test/mapping_tests.py

   1 # tests common to dict and UserDict
   2 import unittest
   3 import UserDict
   4 import test_support
   5
   6
   7 class BasicTestMappingProtocol(unittest.TestCase):
   8     # This base class can be used to check that an object conforms to the
   9     # mapping protocol
  10
  11     # Functions that can be useful to override to adapt to dictionary
  12     # semantics
  13     type2test = None # which class is being tested (overwrite in subclasses)
  14
  15     def _reference(self):
  16         """Return a dictionary of values which are invariant by storage
  17         in the object under test."""
  18         return {1:2, "key1":"value1", "key2":(1,2,3)}
  19     def _empty_mapping(self):
  20         """Return an empty mapping object"""
  21         return self.type2test()
  22     def _full_mapping(self, data):
  23         """Return a mapping object with the value contained in data
  24         dictionary"""
  25         x = self._empty_mapping()
  26         for key, value in data.items():
  27             x[key] = value
  28         return x
  29
  30     def __init__(self, *args, **kw):
  31         unittest.TestCase.__init__(self, *args, **kw)
  32         self.reference = self._reference().copy()
  33
  34         # A (key, value) pair not in the mapping
  35         key, value = self.reference.popitem()
  36         self.other = {key:value}
  37
  38         # A (key, value) pair in the mapping
  39         key, value = self.reference.popitem()
  40         self.inmapping = {key:value}
  41         self.reference[key] = value
  42
  43     def test_read(self):
  44         # Test for read only operations on mapping
  45         p = self._empty_mapping()
  46         p1 = dict(p) #workaround for singleton objects
  47         d = self._full_mapping(self.reference)
  48         if d is p:
  49             p = p1
  50         #Indexing
  51         for key, value in self.reference.items():
  52             self.assertEqual(d[key], value)
  53         knownkey = self.other.keys()[0]
  54         self.assertRaises(KeyError, lambda:d[knownkey])
  55         #len
  56         self.assertEqual(len(p), 0)
  57         self.assertEqual(len(d), len(self.reference))
  58         #in
  59         for k in self.reference:
  60             self.assertIn(k, d)
  61         for k in self.other:
  62             self.assertNotIn(k, d)
  63         #has_key
  64         with test_support.check_py3k_warnings(quiet=True):
  65             for k in self.reference:
  66                 self.assertTrue(d.has_key(k))
  67             for k in self.other:
  68                 self.assertFalse(d.has_key(k))
  69         #cmp
  70         self.assertEqual(cmp(p,p), 0)
  71         self.assertEqual(cmp(d,d), 0)
  72         self.assertEqual(cmp(p,d), -1)
  73         self.assertEqual(cmp(d,p), 1)
  74         #__non__zero__
  75         if p: self.fail("Empty mapping must compare to False")
  76         if not d: self.fail("Full mapping must compare to True")
  77         # keys(), items(), iterkeys() ...
  78         def check_iterandlist(iter, lst, ref):
  79             self.assertTrue(hasattr(iter, 'next'))
  80             self.assertTrue(hasattr(iter, '__iter__'))
  81             x = list(iter)
  82             self.assertTrue(set(x)==set(lst)==set(ref))
  83         check_iterandlist(d.iterkeys(), d.keys(), self.reference.keys())
  84         check_iterandlist(iter(d), d.keys(), self.reference.keys())
  85         check_iterandlist(d.itervalues(), d.values(), self.reference.values())
  86         check_iterandlist(d.iteritems(), d.items(), self.reference.items())
  87         #get
  88         key, value = d.iteritems().next()
  89         knownkey, knownvalue = self.other.iteritems().next()
  90         self.assertEqual(d.get(key, knownvalue), value)
  91         self.assertEqual(d.get(knownkey, knownvalue), knownvalue)
  92         self.assertNotIn(knownkey, d)
  93
  94     def test_write(self):
  95         # Test for write operations on mapping
  96         p = self._empty_mapping()
  97         #Indexing
  98         for key, value in self.reference.items():
  99             p[key] = value
 100             self.assertEqual(p[key], value)
 101         for key in self.reference.keys():
 102             del p[key]
 103             self.assertRaises(KeyError, lambda:p[key])
 104         p = self._empty_mapping()
 105         #update
 106         p.update(self.reference)
 107         self.assertEqual(dict(p), self.reference)
 108         items = p.items()
 109         p = self._empty_mapping()
 110         p.update(items)
 111         self.assertEqual(dict(p), self.reference)
 112         d = self._full_mapping(self.reference)
 113         #setdefault
 114         key, value = d.iteritems().next()
 115         knownkey, knownvalue = self.other.iteritems().next()
 116         self.assertEqual(d.setdefault(key, knownvalue), value)
 117         self.assertEqual(d[key], value)
 118         self.assertEqual(d.setdefault(knownkey, knownvalue), knownvalue)
 119         self.assertEqual(d[knownkey], knownvalue)
 120         #pop
 121         self.assertEqual(d.pop(knownkey), knownvalue)
 122         self.assertNotIn(knownkey, d)
 123         self.assertRaises(KeyError, d.pop, knownkey)
 124         default = 909
 125         d[knownkey] = knownvalue
 126         self.assertEqual(d.pop(knownkey, default), knownvalue)
 127         self.assertNotIn(knownkey, d)
 128         self.assertEqual(d.pop(knownkey, default), default)
 129         #popitem
 130         key, value = d.popitem()
 131         self.assertNotIn(key, d)
 132         self.assertEqual(value, self.reference[key])
 133         p=self._empty_mapping()
 134         self.assertRaises(KeyError, p.popitem)
 135
 136     def test_constructor(self):
 137         self.assertEqual(self._empty_mapping(), self._empty_mapping())
 138
 139     def test_bool(self):
 140         self.assertTrue(not self._empty_mapping())
 141         self.assertTrue(self.reference)
 142         self.assertTrue(bool(self._empty_mapping()) is False)
 143         self.assertTrue(bool(self.reference) is True)
 144
 145     def test_keys(self):
 146         d = self._empty_mapping()
 147         self.assertEqual(d.keys(), [])
 148         d = self.reference
 149         self.assertIn(self.inmapping.keys()[0], d.keys())
 150         self.assertNotIn(self.other.keys()[0], d.keys())
 151         self.assertRaises(TypeError, d.keys, None)
 152
 153     def test_values(self):
 154         d = self._empty_mapping()
 155         self.assertEqual(d.values(), [])
 156
 157         self.assertRaises(TypeError, d.values, None)
 158
 159     def test_items(self):
 160         d = self._empty_mapping()
 161         self.assertEqual(d.items(), [])
 162
 163         self.assertRaises(TypeError, d.items, None)
 164
 165     def test_len(self):
 166         d = self._empty_mapping()
 167         self.assertEqual(len(d), 0)
 168
 169     def test_getitem(self):
 170         d = self.reference
 171         self.assertEqual(d[self.inmapping.keys()[0]], self.inmapping.values()[0])
 172
 173         self.assertRaises(TypeError, d.__getitem__)
 174
 175     def test_update(self):
 176         # mapping argument
 177         d = self._empty_mapping()
 178         d.update(self.other)
 179         self.assertEqual(d.items(), self.other.items())
 180
 181         # No argument
 182         d = self._empty_mapping()
 183         d.update()
 184         self.assertEqual(d, self._empty_mapping())
 185
 186         # item sequence
 187         d = self._empty_mapping()
 188         d.update(self.other.items())
 189         self.assertEqual(d.items(), self.other.items())
 190
 191         # Iterator
 192         d = self._empty_mapping()
 193         d.update(self.other.iteritems())
 194         self.assertEqual(d.items(), self.other.items())
 195
 196         # FIXME: Doesn't work with UserDict
 197         # self.assertRaises((TypeError, AttributeError), d.update, None)
 198         self.assertRaises((TypeError, AttributeError), d.update, 42)
 199
 200         outerself = self
 201         class SimpleUserDict:
 202             def __init__(self):
 203                 self.d = outerself.reference
 204             def keys(self):
 205                 return self.d.keys()
 206             def __getitem__(self, i):
 207                 return self.d[i]
 208         d.clear()
 209         d.update(SimpleUserDict())
 210         i1 = d.items()
 211         i2 = self.reference.items()
 212         i1.sort()
 213         i2.sort()
 214         self.assertEqual(i1, i2)
 215
 216         class Exc(Exception): pass
 217
 218         d = self._empty_mapping()
 219         class FailingUserDict:
 220             def keys(self):
 221                 raise Exc
 222         self.assertRaises(Exc, d.update, FailingUserDict())
 223
 224         d.clear()
 225
 226         class FailingUserDict:
 227             def keys(self):
 228                 class BogonIter:
 229                     def __init__(self):
 230                         self.i = 1
 231                     def __iter__(self):
 232                         return self
 233                     def next(self):
 234                         if self.i:
 235                             self.i = 0
 236                             return 'a'
 237                         raise Exc
 238                 return BogonIter()
 239             def __getitem__(self, key):
 240                 return key
 241         self.assertRaises(Exc, d.update, FailingUserDict())
 242
 243         class FailingUserDict:
 244             def keys(self):
 245                 class BogonIter:
 246                     def __init__(self):
 247                         self.i = ord('a')
 248                     def __iter__(self):
 249                         return self
 250                     def next(self):
 251                         if self.i <= ord('z'):
 252                             rtn = chr(self.i)
 253                             self.i += 1
 254                             return rtn
 255                         raise StopIteration
 256                 return BogonIter()
 257             def __getitem__(self, key):
 258                 raise Exc
 259         self.assertRaises(Exc, d.update, FailingUserDict())
 260
 261         d = self._empty_mapping()
 262         class badseq(object):
 263             def __iter__(self):
 264                 return self
 265             def next(self):
 266                 raise Exc()
 267
 268         self.assertRaises(Exc, d.update, badseq())
 269
 270         self.assertRaises(ValueError, d.update, [(1, 2, 3)])
 271
 272     # no test_fromkeys or test_copy as both os.environ and selves don't support it
 273
 274     def test_get(self):
 275         d = self._empty_mapping()
 276         self.assertTrue(d.get(self.other.keys()[0]) is None)
 277         self.assertEqual(d.get(self.other.keys()[0], 3), 3)
 278         d = self.reference
 279         self.assertTrue(d.get(self.other.keys()[0]) is None)
 280         self.assertEqual(d.get(self.other.keys()[0], 3), 3)
 281         self.assertEqual(d.get(self.inmapping.keys()[0]), self.inmapping.values()[0])
 282         self.assertEqual(d.get(self.inmapping.keys()[0], 3), self.inmapping.values()[0])
 283         self.assertRaises(TypeError, d.get)
 284         self.assertRaises(TypeError, d.get, None, None, None)
 285
 286     def test_setdefault(self):
 287         d = self._empty_mapping()
 288         self.assertRaises(TypeError, d.setdefault)
 289
 290     def test_popitem(self):
 291         d = self._empty_mapping()
 292         self.assertRaises(KeyError, d.popitem)
 293         self.assertRaises(TypeError, d.popitem, 42)
 294
 295     def test_pop(self):
 296         d = self._empty_mapping()
 297         k, v = self.inmapping.items()[0]
 298         d[k] = v
 299         self.assertRaises(KeyError, d.pop, self.other.keys()[0])
 300
 301         self.assertEqual(d.pop(k), v)
 302         self.assertEqual(len(d), 0)
 303
 304         self.assertRaises(KeyError, d.pop, k)
 305
 306
 307 class TestMappingProtocol(BasicTestMappingProtocol):
 308     def test_constructor(self):
 309         BasicTestMappingProtocol.test_constructor(self)
 310         self.assertTrue(self._empty_mapping() is not self._empty_mapping())
 311         self.assertEqual(self.type2test(x=1, y=2), {"x": 1, "y": 2})
 312
 313     def test_bool(self):
 314         BasicTestMappingProtocol.test_bool(self)
 315         self.assertTrue(not self._empty_mapping())
 316         self.assertTrue(self._full_mapping({"x": "y"}))
 317         self.assertTrue(bool(self._empty_mapping()) is False)
 318         self.assertTrue(bool(self._full_mapping({"x": "y"})) is True)
 319
 320     def test_keys(self):
 321         BasicTestMappingProtocol.test_keys(self)
 322         d = self._empty_mapping()
 323         self.assertEqual(d.keys(), [])
 324         d = self._full_mapping({'a': 1, 'b': 2})
 325         k = d.keys()
 326         self.assertIn('a', k)
 327         self.assertIn('b', k)
 328         self.assertNotIn('c', k)
 329
 330     def test_values(self):
 331         BasicTestMappingProtocol.test_values(self)
 332         d = self._full_mapping({1:2})
 333         self.assertEqual(d.values(), [2])
 334
 335     def test_items(self):
 336         BasicTestMappingProtocol.test_items(self)
 337
 338         d = self._full_mapping({1:2})
 339         self.assertEqual(d.items(), [(1, 2)])
 340
 341     def test_has_key(self):
 342         d = self._empty_mapping()
 343         self.assertTrue(not d.has_key('a'))
 344         d = self._full_mapping({'a': 1, 'b': 2})
 345         k = d.keys()
 346         k.sort()
 347         self.assertEqual(k, ['a', 'b'])
 348
 349         self.assertRaises(TypeError, d.has_key)
 350
 351     def test_contains(self):
 352         d = self._empty_mapping()
 353         self.assertNotIn('a', d)
 354         self.assertTrue(not ('a' in d))
 355         self.assertTrue('a' not in d)
 356         d = self._full_mapping({'a': 1, 'b': 2})
 357         self.assertIn('a', d)
 358         self.assertIn('b', d)
 359         self.assertNotIn('c', d)
 360
 361         self.assertRaises(TypeError, d.__contains__)
 362
 363     def test_len(self):
 364         BasicTestMappingProtocol.test_len(self)
 365         d = self._full_mapping({'a': 1, 'b': 2})
 366         self.assertEqual(len(d), 2)
 367
 368     def test_getitem(self):
 369         BasicTestMappingProtocol.test_getitem(self)
 370         d = self._full_mapping({'a': 1, 'b': 2})
 371         self.assertEqual(d['a'], 1)
 372         self.assertEqual(d['b'], 2)
 373         d['c'] = 3
 374         d['a'] = 4
 375         self.assertEqual(d['c'], 3)
 376         self.assertEqual(d['a'], 4)
 377         del d['b']
 378         self.assertEqual(d, {'a': 4, 'c': 3})
 379
 380         self.assertRaises(TypeError, d.__getitem__)
 381
 382     def test_clear(self):
 383         d = self._full_mapping({1:1, 2:2, 3:3})
 384         d.clear()
 385         self.assertEqual(d, {})
 386
 387         self.assertRaises(TypeError, d.clear, None)
 388
 389     def test_update(self):
 390         BasicTestMappingProtocol.test_update(self)
 391         # mapping argument
 392         d = self._empty_mapping()
 393         d.update({1:100})
 394         d.update({2:20})
 395         d.update({1:1, 2:2, 3:3})
 396         self.assertEqual(d, {1:1, 2:2, 3:3})
 397
 398         # no argument
 399         d.update()
 400         self.assertEqual(d, {1:1, 2:2, 3:3})
 401
 402         # keyword arguments
 403         d = self._empty_mapping()
 404         d.update(x=100)
 405         d.update(y=20)
 406         d.update(x=1, y=2, z=3)
 407         self.assertEqual(d, {"x":1, "y":2, "z":3})
 408
 409         # item sequence
 410         d = self._empty_mapping()
 411         d.update([("x", 100), ("y", 20)])
 412         self.assertEqual(d, {"x":100, "y":20})
 413
 414         # Both item sequence and keyword arguments
 415         d = self._empty_mapping()
 416         d.update([("x", 100), ("y", 20)], x=1, y=2)
 417         self.assertEqual(d, {"x":1, "y":2})
 418
 419         # iterator
 420         d = self._full_mapping({1:3, 2:4})
 421         d.update(self._full_mapping({1:2, 3:4, 5:6}).iteritems())
 422         self.assertEqual(d, {1:2, 2:4, 3:4, 5:6})
 423
 424         class SimpleUserDict:
 425             def __init__(self):
 426                 self.d = {1:1, 2:2, 3:3}
 427             def keys(self):
 428                 return self.d.keys()
 429             def __getitem__(self, i):
 430                 return self.d[i]
 431         d.clear()
 432         d.update(SimpleUserDict())
 433         self.assertEqual(d, {1:1, 2:2, 3:3})
 434
 435     def test_fromkeys(self):
 436         self.assertEqual(self.type2test.fromkeys('abc'), {'a':None, 'b':None, 'c':None})
 437         d = self._empty_mapping()
 438         self.assertTrue(not(d.fromkeys('abc') is d))
 439         self.assertEqual(d.fromkeys('abc'), {'a':None, 'b':None, 'c':None})
 440         self.assertEqual(d.fromkeys((4,5),0), {4:0, 5:0})
 441         self.assertEqual(d.fromkeys([]), {})
 442         def g():
 443             yield 1
 444         self.assertEqual(d.fromkeys(g()), {1:None})
 445         self.assertRaises(TypeError, {}.fromkeys, 3)
 446         class dictlike(self.type2test): pass
 447         self.assertEqual(dictlike.fromkeys('a'), {'a':None})
 448         self.assertEqual(dictlike().fromkeys('a'), {'a':None})
 449         self.assertTrue(dictlike.fromkeys('a').__class__ is dictlike)
 450         self.assertTrue(dictlike().fromkeys('a').__class__ is dictlike)
 451         # FIXME: the following won't work with UserDict, because it's an old style class
 452         # self.assertTrue(type(dictlike.fromkeys('a')) is dictlike)
 453         class mydict(self.type2test):
 454             def __new__(cls):
 455                 return UserDict.UserDict()
 456         ud = mydict.fromkeys('ab')
 457         self.assertEqual(ud, {'a':None, 'b':None})
 458         # FIXME: the following won't work with UserDict, because it's an old style class
 459         # self.assertIsInstance(ud, UserDict.UserDict)
 460         self.assertRaises(TypeError, dict.fromkeys)
 461
 462         class Exc(Exception): pass
 463
 464         class baddict1(self.type2test):
 465             def __init__(self):
 466                 raise Exc()
 467
 468         self.assertRaises(Exc, baddict1.fromkeys, [1])
 469
 470         class BadSeq(object):
 471             def __iter__(self):
 472                 return self
 473             def next(self):
 474                 raise Exc()
 475
 476         self.assertRaises(Exc, self.type2test.fromkeys, BadSeq())
 477
 478         class baddict2(self.type2test):
 479             def __setitem__(self, key, value):
 480                 raise Exc()
 481
 482         self.assertRaises(Exc, baddict2.fromkeys, [1])
 483
 484     def test_copy(self):
 485         d = self._full_mapping({1:1, 2:2, 3:3})
 486         self.assertEqual(d.copy(), {1:1, 2:2, 3:3})
 487         d = self._empty_mapping()
 488         self.assertEqual(d.copy(), d)
 489         self.assertIsInstance(d.copy(), d.__class__)
 490         self.assertRaises(TypeError, d.copy, None)
 491
 492     def test_get(self):
 493         BasicTestMappingProtocol.test_get(self)
 494         d = self._empty_mapping()
 495         self.assertTrue(d.get('c') is None)
 496         self.assertEqual(d.get('c', 3), 3)
 497         d = self._full_mapping({'a' : 1, 'b' : 2})
 498         self.assertTrue(d.get('c') is None)
 499         self.assertEqual(d.get('c', 3), 3)
 500         self.assertEqual(d.get('a'), 1)
 501         self.assertEqual(d.get('a', 3), 1)
 502
 503     def test_setdefault(self):
 504         BasicTestMappingProtocol.test_setdefault(self)
 505         d = self._empty_mapping()
 506         self.assertTrue(d.setdefault('key0') is None)
 507         d.setdefault('key0', [])
 508         self.assertTrue(d.setdefault('key0') is None)
 509         d.setdefault('key', []).append(3)
 510         self.assertEqual(d['key'][0], 3)
 511         d.setdefault('key', []).append(4)
 512         self.assertEqual(len(d['key']), 2)
 513
 514     def test_popitem(self):
 515         BasicTestMappingProtocol.test_popitem(self)
 516         for copymode in -1, +1:
 517             # -1: b has same structure as a
 518             # +1: b is a.copy()
 519             for log2size in range(12):
 520                 size = 2**log2size
 521                 a = self._empty_mapping()
 522                 b = self._empty_mapping()
 523                 for i in range(size):
 524                     a[repr(i)] = i
 525                     if copymode < 0:
 526                         b[repr(i)] = i
 527                 if copymode > 0:
 528                     b = a.copy()
 529                 for i in range(size):
 530                     ka, va = ta = a.popitem()
 531                     self.assertEqual(va, int(ka))
 532                     kb, vb = tb = b.popitem()
 533                     self.assertEqual(vb, int(kb))
 534                     self.assertTrue(not(copymode < 0 and ta != tb))
 535                 self.assertTrue(not a)
 536                 self.assertTrue(not b)
 537
 538     def test_pop(self):
 539         BasicTestMappingProtocol.test_pop(self)
 540
 541         # Tests for pop with specified key
 542         d = self._empty_mapping()
 543         k, v = 'abc', 'def'
 544
 545         # verify longs/ints get same value when key > 32 bits (for 64-bit archs)
 546         # see SF bug #689659
 547         x = 4503599627370496L
 548         y = 4503599627370496
 549         h = self._full_mapping({x: 'anything', y: 'something else'})
 550         self.assertEqual(h[x], h[y])
 551
 552         self.assertEqual(d.pop(k, v), v)
 553         d[k] = v
 554         self.assertEqual(d.pop(k, 1), v)
 555
 556
 557 class TestHashMappingProtocol(TestMappingProtocol):
 558
 559     def test_getitem(self):
 560         TestMappingProtocol.test_getitem(self)
 561         class Exc(Exception): pass
 562
 563         class BadEq(object):
 564             def __eq__(self, other):
 565                 raise Exc()
 566             def __hash__(self):
 567                 return 24
 568
 569         d = self._empty_mapping()
 570         d[BadEq()] = 42
 571         self.assertRaises(KeyError, d.__getitem__, 23)
 572
 573         class BadHash(object):
 574             fail = False
 575             def __hash__(self):
 576                 if self.fail:
 577                     raise Exc()
 578                 else:
 579                     return 42
 580
 581         d = self._empty_mapping()
 582         x = BadHash()
 583         d[x] = 42
 584         x.fail = True
 585         self.assertRaises(Exc, d.__getitem__, x)
 586
 587     def test_fromkeys(self):
 588         TestMappingProtocol.test_fromkeys(self)
 589         class mydict(self.type2test):
 590             def __new__(cls):
 591                 return UserDict.UserDict()
 592         ud = mydict.fromkeys('ab')
 593         self.assertEqual(ud, {'a':None, 'b':None})
 594         self.assertIsInstance(ud, UserDict.UserDict)
 595
 596     def test_pop(self):
 597         TestMappingProtocol.test_pop(self)
 598
 599         class Exc(Exception): pass
 600
 601         class BadHash(object):
 602             fail = False
 603             def __hash__(self):
 604                 if self.fail:
 605                     raise Exc()
 606                 else:
 607                     return 42
 608
 609         d = self._empty_mapping()
 610         x = BadHash()
 611         d[x] = 42
 612         x.fail = True
 613         self.assertRaises(Exc, d.pop, x)
 614
 615     def test_mutatingiteration(self):
 616         d = self._empty_mapping()
 617         d[1] = 1
 618         try:
 619             for i in d:
 620                 d[i+1] = 1
 621         except RuntimeError:
 622             pass
 623         else:
 624             self.fail("changing dict size during iteration doesn't raise Error")
 625
 626     def test_repr(self):
 627         d = self._empty_mapping()
 628         self.assertEqual(repr(d), '{}')
 629         d[1] = 2
 630         self.assertEqual(repr(d), '{1: 2}')
 631         d = self._empty_mapping()
 632         d[1] = d
 633         self.assertEqual(repr(d), '{1: {...}}')
 634
 635         class Exc(Exception): pass
 636
 637         class BadRepr(object):
 638             def __repr__(self):
 639                 raise Exc()
 640
 641         d = self._full_mapping({1: BadRepr()})
 642         self.assertRaises(Exc, repr, d)
 643
 644     def test_le(self):
 645         self.assertTrue(not (self._empty_mapping() < self._empty_mapping()))
 646         self.assertTrue(not (self._full_mapping({1: 2}) < self._full_mapping({1L: 2L})))
 647
 648         class Exc(Exception): pass
 649
 650         class BadCmp(object):
 651             def __eq__(self, other):
 652                 raise Exc()
 653             def __hash__(self):
 654                 return 42
 655
 656         d1 = self._full_mapping({BadCmp(): 1})
 657         d2 = self._full_mapping({1: 1})
 658         try:
 659             d1 < d2
 660         except Exc:
 661             pass
 662         else:
 663             self.fail("< didn't raise Exc")
 664
 665     def test_setdefault(self):
 666         TestMappingProtocol.test_setdefault(self)
 667
 668         class Exc(Exception): pass
 669
 670         class BadHash(object):
 671             fail = False
 672             def __hash__(self):
 673                 if self.fail:
 674                     raise Exc()
 675                 else:
 676                     return 42
 677
 678         d = self._empty_mapping()
 679         x = BadHash()
 680         d[x] = 42
 681         x.fail = True
 682         self.assertRaises(Exc, d.setdefault, x, [])