bpo-43102: Set namedtuple __new__'s internal builtins to a dict. (GH-24439)

diff --git a/Lib/collections/__init__.py b/Lib/collections/__init__.py
index 7d338131d6740d7f1c51d398ff2be6e453fc78a8..6fe3c4c5aa541d7ba01e6bce059c7c8c92a42494 100644 (file)
--- a/Lib/collections/__init__.py
+++ b/Lib/collections/__init__.py
@@ -407,7 +407,7 @@ def namedtuple(typename, field_names, *, rename=False, defaults=None, module=Non
 
     namespace = {
         '_tuple_new': tuple_new,
-        '__builtins__': None,
+        '__builtins__': {},
         '__name__': f'namedtuple_{typename}',
     }
     code = f'lambda _cls, {arg_list}: _tuple_new(_cls, ({arg_list}))'

diff --git a/Lib/test/test_collections.py b/Lib/test/test_collections.py
index a1ca958257adf6af64869a551fd658623b701be8..befb7ab436c40af836509a985845f82188cfd2e9 100644 (file)
--- a/Lib/test/test_collections.py
+++ b/Lib/test/test_collections.py
@@ -681,6 +681,11 @@ class TestNamedTuple(unittest.TestCase):
         self.assertEqual(np.x, 1)
         self.assertEqual(np.y, 2)
 
+    def test_new_builtins_issue_43102(self):
+        self.assertEqual(
+            namedtuple('C', ()).__new__.__globals__['__builtins__'],
+            {})
+
 
 ################################################################################
 ### Abstract Base Classes

diff --git a/Misc/NEWS.d/next/Library/2021-02-03-22-55-27.bpo-43102.TSlZ6J.rst b/Misc/NEWS.d/next/Library/2021-02-03-22-55-27.bpo-43102.TSlZ6J.rst
new file mode 100644 (file)
index 0000000..985fd68
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2021-02-03-22-55-27.bpo-43102.TSlZ6J.rst
@@ -0,0 +1,2 @@
+The namedtuple __new__ method had its __builtins__ set to None instead
+of an actual dictionary.  This created problems for introspection tools.