Deprecate nametuple._asdict()

2 files changed, 8 insertions, 2 deletions

diff --git a/Lib/collections/__init__.py b/Lib/collections/__init__.py
index 5fd54e8..24daa34 100644
--- a/Lib/collections/__init__.py
+++ b/Lib/collections/__init__.py
@@ -280,6 +280,9 @@ class {typename}(tuple):
         '''Return a new OrderedDict which maps field names to their values.
            This method is obsolete.  Use vars(nt) or nt.__dict__ instead.
         '''
+        import warnings
+        warnings.warn('_asdict() is deprecated.  Use vars(nt) instead.',
+                      DeprecationWarning, stacklevel=2)
         return self.__dict__
 
     def __getnewargs__(self):
diff --git a/Lib/test/test_collections.py b/Lib/test/test_collections.py
index 8033031..12bd952 100644
--- a/Lib/test/test_collections.py
+++ b/Lib/test/test_collections.py
@@ -217,8 +217,11 @@ class TestNamedTuple(unittest.TestCase):
         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
+        self.assertEqual(p.__dict__,
+                         OrderedDict([('x', 11), ('y', 22)]))               # test __dict__ attribute
+        self.assertEqual(vars(p), p.__dict__)                               # verify that vars() works
+        with self.assertWarns(DeprecationWarning):                          # check deprecate of _asdict
+            p._asdict()
 
         try:
             p._replace(x=1, error=2)