Encapsulate the _classcell parameter

Author: johnslavik

Lib/collections/__init__.py

@@ -358,30 +358,7 @@ def __ror__(self, other):
 except ImportError:
     _tuplegetter = lambda index, doc: property(_itemgetter(index), doc=doc)
 
-def namedtuple(typename, field_names, *, rename=False, defaults=None, module=None, _classcell=None):
-    """Returns a new subclass of tuple with named fields.
-
-    >>> Point = namedtuple('Point', ['x', 'y'])
-    >>> Point.__doc__                   # docstring for the new class
-    'Point(x, y)'
-    >>> p = Point(11, y=22)             # instantiate with positional args or keywords
-    >>> p[0] + p[1]                     # indexable like a plain tuple
-    33
-    >>> x, y = p                        # unpack like a regular tuple
-    >>> x, y
-    (11, 22)
-    >>> p.x + p.y                       # fields also accessible by name
-    33
-    >>> d = p._asdict()                 # convert to a dictionary
-    >>> d['x']
-    11
-    >>> Point(**d)                      # convert from a dictionary
-    Point(x=11, y=22)
-    >>> p._replace(x=100)               # _replace() is like str.replace() but targets named fields
-    Point(x=100, y=22)
-
-    """
-
+def _namedtuple(typename, field_names, *, rename=False, defaults=None, module=None, classcell=None):
     # Validate the field names.  At the user's option, either generate an error
     # message or automatically replace the field name with a valid name.
     if isinstance(field_names, str):
@@ -509,8 +486,8 @@ def __getnewargs__(self):
         '__match_args__': field_names,
     }
 
-    if _classcell is not None:
-        class_namespace["__classcell__"] = _classcell
+    if classcell is not None:
+        class_namespace["__classcell__"] = classcell
 
     for index, name in enumerate(field_names):
         doc = _sys.intern(f'Alias for field number {index}')
@@ -536,6 +513,30 @@ def __getnewargs__(self):
 
     return result
 
+def namedtuple(typename, field_names, *, rename=False, defaults=None, module=None):
+    """Returns a new subclass of tuple with named fields.
+
+    >>> Point = namedtuple('Point', ['x', 'y'])
+    >>> Point.__doc__                   # docstring for the new class
+    'Point(x, y)'
+    >>> p = Point(11, y=22)             # instantiate with positional args or keywords
+    >>> p[0] + p[1]                     # indexable like a plain tuple
+    33
+    >>> x, y = p                        # unpack like a regular tuple
+    >>> x, y
+    (11, 22)
+    >>> p.x + p.y                       # fields also accessible by name
+    33
+    >>> d = p._asdict()                 # convert to a dictionary
+    >>> d['x']
+    11
+    >>> Point(**d)                      # convert from a dictionary
+    Point(x=11, y=22)
+    >>> p._replace(x=100)               # _replace() is like str.replace() but targets named fields
+    Point(x=100, y=22)
+
+    """
+    return _namedtuple(typename, field_names, rename=rename, defaults=defaults, module=module)
 
 ########################################################################
 ###  Counter

Lib/typing.py

@@ -2929,9 +2929,9 @@ def __round__(self, ndigits: int = 0) -> T:
         pass
 
 
-def _make_nmtuple(name, fields, annotate_func, module, defaults = (), _classcell=None):
-    nm_tpl = collections.namedtuple(name, fields, defaults=defaults,
-                                    module=module, _classcell=_classcell)
+def _make_nmtuple(name, fields, annotate_func, module, defaults = (), classcell=None):
+    nm_tpl = collections._namedtuple(name, fields, defaults=defaults,
+                                     module=module, classcell=classcell)
     nm_tpl.__annotate__ = nm_tpl.__new__.__annotate__ = annotate_func
     return nm_tpl
 
@@ -2999,8 +2999,8 @@ def annotate(format):
                                 f"{'s' if len(default_names) > 1 else ''} "
                                 f"{', '.join(default_names)}")
         nm_tpl = _make_nmtuple(typename, field_names, annotate,
-                               defaults=[ns[n] for n in default_names],
-                               module=ns['__module__'], _classcell=ns.pop("__classcell__", None))
+                               defaults=[ns[n] for n in default_names], module=ns['__module__'],
+                               classcell=ns.pop('__classcell__', None))
         nm_tpl.__bases__ = bases
         if Generic in bases:
             class_getitem = _generic_class_getitem