Issue #25628: Make namedtuple "rename" and "verbose" parameters keyword-only.

Doc/library/collections.rst

@@ -763,7 +763,7 @@ Named tuples assign meaning to each position in a tuple and allow for more reada
 self-documenting code.  They can be used wherever regular tuples are used, and
 they add the ability to access fields by name instead of position index.
 
-.. function:: namedtuple(typename, field_names, verbose=False, rename=False)
+.. function:: namedtuple(typename, field_names, *, verbose=False, rename=False)
 
     Returns a new tuple subclass named *typename*.  The new subclass is used to
     create tuple-like objects that have fields accessible by attribute lookup as
@@ -799,7 +799,11 @@ they add the ability to access fields by name instead of position index.
     a namedtuple.
 
     .. versionchanged:: 3.1
-        Added support for *rename*.
+       Added support for *rename*.
+
+    .. versionchanged:: 3.6
+       The *verbose* and *rename* parameters became
+       :ref:`keyword-only arguments <keyword-only_parameter>`.
 
 
 .. doctest::

Lib/collections/__init__.py

@@ -353,7 +353,7 @@ _field_template = '''\
     {name} = _property(_itemgetter({index:d}), doc='Alias for field number {index:d}')
 '''
 
-def namedtuple(typename, field_names, verbose=False, rename=False):
+def namedtuple(typename, field_names, *, verbose=False, rename=False):
     """Returns a new subclass of tuple with named fields.
 
     >>> Point = namedtuple('Point', ['x', 'y'])

Lib/test/test_collections.py

@@ -412,6 +412,18 @@ class TestNamedTuple(unittest.TestCase):
         self.assertEqual(NTColor._fields, ('red', 'green', 'blue'))
         globals().pop('NTColor', None)          # clean-up after this test
 
+    def test_keyword_only_arguments(self):
+        # See issue 25628
+        with support.captured_stdout() as template:
+            NT = namedtuple('NT', ['x', 'y'], verbose=True)
+        self.assertIn('class NT', NT._source)
+        with self.assertRaises(TypeError):
+            NT = namedtuple('NT', ['x', 'y'], True)
+
+        NT = namedtuple('NT', ['abc', 'def'], rename=True)
+        self.assertEqual(NT._fields, ('abc', '_1'))
+        with self.assertRaises(TypeError):
+            NT = namedtuple('NT', ['abc', 'def'], False, True)
 
     def test_namedtuple_subclass_issue_24931(self):
         class Point(namedtuple('_Point', ['x', 'y'])):

Misc/NEWS

@@ -73,6 +73,9 @@ Library
   to ref count problem introduced in code for Issue #27038 in 3.6.0a3.
   Patch by Xiang Zhang.
 
+- Issue #25628:  The *verbose* and *rename* parameters for collections.namedtuple
+  are now keyword-only.
+
 - Issue #12345: Add mathemathical constant tau to math and cmath. See also
   PEP 628.