* Constructors of subclasses of some buitin classes (e.g. tuple, list,
frozenset) no longer accept arbitrary keyword arguments.
* Subclass of set can now define a __new__() method with additional
keyword parameters without overriding also __init__().
Previously, the result could have been an instance of a subclass of int.
Also revert bpo-26202 and make attributes start, stop and step of the range
object having exact type int.
Add private function _PyNumber_Index() which preserves the old behavior
of PyNumber_Index() for performance to use it in the conversion functions
like PyLong_AsLong().
* bpo-32492: 2.5x speed up in namedtuple attribute access using C fast path
* Add News entry
* fixup! bpo-32492: 2.5x speed up in namedtuple attribute access using C fast path
* Check for tuple in the __get__ of the new descriptor and don't cache the descriptor itself
* Don't inherit from property. Implement GC methods to handle __doc__
* Add a test for the docstring substitution in descriptors
* Update NEWS entry to reflect time against 3.7 branch
* Simplify implementation with argument clinic, better error messages, only __new__
* Use positional-only parameters for the __new__
* Use PyTuple_GET_SIZE and PyTuple_GET_ITEM to tighter the implementation of tuplegetterdescr_get
* Implement __set__ to make tuplegetter a data descriptor
* Use Py_INCREF now that we inline PyTuple_GetItem
* Apply the valid_index() function, saving one test
* Move Py_None test out of the critical path.
Serhiy Storchaka
Raymond Hettinger
Pablo Galindo