Complete and neaten-up namedtuple's replacement of builtin function lookups with derefs (GH-11794)

Author: rhettinger

Lib/collections/__init__.py

@@ -390,7 +390,7 @@ def namedtuple(typename, field_names, *, rename=False, defaults=None, module=Non
  arg_list = repr(field_names).replace("'", "")[1:-1]
  repr_fmt = '(' + ', '.join(f'{name}=%r' for name in field_names) + ')'
  tuple_new = tuple.__new__
- _len = len
+ _dict, _tuple, _len, _map, _zip = dict, tuple, len, map, zip
 
  # Create all the named tuple methods to be added to the class namespace
 
@@ -414,7 +414,7 @@ def _make(cls, iterable):
  'or iterable')
 
  def _replace(_self, **kwds):
- result = _self._make(map(kwds.pop, field_names, _self))
+ result = _self._make(_map(kwds.pop, field_names, _self))
  if kwds:
  raise ValueError(f'Got unexpected field names: {list(kwds)!r}')
  return result
@@ -426,18 +426,15 @@ def __repr__(self):
  'Return a nicely formatted representation string'
  return self.__class__.__name__ + repr_fmt % self
 
- _dict, _zip = dict, zip
-
  def _asdict(self):
  'Return a new dict which maps field names to their values.'
  return _dict(_zip(self._fields, self))
 
  def __getnewargs__(self):
  'Return self as a plain tuple. Used by copy and pickle.'
- return tuple(self)
+ return _tuple(self)
 
  # Modify function metadata to help with introspection and debugging
-
  for method in (__new__, _make.__func__, _replace,
  __repr__, _asdict, __getnewargs__):
  method.__qualname__ = f'{typename}.{method.__name__}'