Allow all alphanumeric and underscores in type and field names.

Lib/collections.py

@@ -24,7 +24,7 @@ def NamedTuple(typename, s):
     """
 
     field_names = s.split()
-    if not ''.join([typename] + field_names).replace('_', '').isalpha():
+    if not ''.join([typename] + field_names).replace('_', '').isalnum():
         raise ValueError('Type names and field names can only contain alphanumeric characters and underscores')
     argtxt = ', '.join(field_names)
     reprtxt = ', '.join('%s=%%r' % name for name in field_names)

Lib/test/test_collections.py

@@ -11,6 +11,9 @@ class TestNamedTuple(unittest.TestCase):
         self.assertEqual(Point.__slots__, ())
         self.assertEqual(Point.__module__, __name__)
         self.assertEqual(Point.__getitem__, tuple.__getitem__)
+        self.assertRaises(ValueError, NamedTuple, 'abc%', 'def ghi')
+        self.assertRaises(ValueError, NamedTuple, 'abc', 'def g%hi')
+        NamedTuple('Point0', 'x1 y2')   # Verify that numbers are allowed in names
 
     def test_instance(self):
         Point = NamedTuple('Point', 'x y')