Issue #18015: Fix unpickling of 2.7.3 and 2.7.4 namedtuples.

Doc/library/collections.rst

@@ -638,6 +638,12 @@ Example:
        def __getnewargs__(self):
            'Return self as a plain tuple.   Used by copy and pickle.'
            return tuple(self)
+   <BLANKLINE>
+       __dict__ = _property(_asdict)
+   <BLANKLINE>
+       def __getstate__(self):
+           'Exclude the OrderedDict from pickling'
+           pass
    <BLANKLINE>
        x = _property(_itemgetter(0), doc='Alias for field number 0')
    <BLANKLINE>

Lib/collections.py

@@ -270,6 +270,12 @@ class {typename}(tuple):
         'Return self as a plain tuple.  Used by copy and pickle.'
         return tuple(self)
 
+    __dict__ = _property(_asdict)
+
+    def __getstate__(self):
+        'Exclude the OrderedDict from pickling'
+        pass
+
 {field_defs}
 '''
 

Lib/test/test_collections.py

@@ -17,6 +17,43 @@ from collections import Sequence, MutableSequence
 
 TestNT = namedtuple('TestNT', 'x y z')    # type used for pickle tests
 
+py273_named_tuple_pickle = '''\
+ccopy_reg
+_reconstructor
+p0
+(ctest.test_collections
+TestNT
+p1
+c__builtin__
+tuple
+p2
+(I10
+I20
+I30
+tp3
+tp4
+Rp5
+ccollections
+OrderedDict
+p6
+((lp7
+(lp8
+S'x'
+p9
+aI10
+aa(lp10
+S'y'
+p11
+aI20
+aa(lp12
+S'z'
+p13
+aI30
+aatp14
+Rp15
+b.
+'''
+
 class TestNamedTuple(unittest.TestCase):
 
     def test_factory(self):
@@ -78,12 +115,12 @@ class TestNamedTuple(unittest.TestCase):
         self.assertRaises(TypeError, eval, 'Point(XXX=1, y=2)', locals())   # wrong keyword argument
         self.assertRaises(TypeError, eval, 'Point(x=1)', locals())          # missing keyword argument
         self.assertEqual(repr(p), 'Point(x=11, y=22)')
-        self.assertNotIn('__dict__', dir(p))                              # verify instance has no dict
         self.assertNotIn('__weakref__', dir(p))
         self.assertEqual(p, Point._make([11, 22]))                          # test _make classmethod
         self.assertEqual(p._fields, ('x', 'y'))                             # test _fields attribute
         self.assertEqual(p._replace(x=1), (1, 22))                          # test _replace method
         self.assertEqual(p._asdict(), dict(x=11, y=22))                     # test _asdict method
+        self.assertEqual(vars(p), p._asdict())                              # verify that vars() works
 
         try:
             p._replace(x=1, error=2)
@@ -215,6 +252,11 @@ class TestNamedTuple(unittest.TestCase):
         # test __getnewargs__
         self.assertEqual(t.__getnewargs__(), values)
 
+    def test_pickling_bug_18015(self):
+        # http://bugs.python.org/issue18015
+        pt = pickle.loads(py273_named_tuple_pickle)
+        self.assertEqual(pt.x, 10)
+
 class ABCTestCase(unittest.TestCase):
 
     def validate_abstract_methods(self, abc, *names):

Misc/NEWS

@@ -19,6 +19,8 @@ Library
 
 - Issue #17981: Closed socket on error in SysLogHandler.
 
+- Issue #18015: Fix unpickling of 2.7.3 and 2.7.4 namedtuples.
+
 - Issue #17754: Make ctypes.util.find_library() independent of the locale.
 
 - Fix typos in the multiprocessing module.