:Editor: Raymond Hettinger

from datetime import date

from math import cos, radians

from unicodedata import normalize

import re

import math

was lifted.

(Contributed by Serhiy Storchaka in:issue:`32489`.)

* The:class:`int` type now has a new:meth:`~int.as_integer_ratio` method

compatible with the existing:meth:`float.as_integer_ratio` method.

(Contributed by Lisa Roach in:issue:`33073`.)

* The:class:`bool`,:class:`int`, and:class:`fractions.Fraction` types

now have an:meth:`~int.as_integer_ratio` method like that found in

:class:`float` and:class:`decimal.Decimal`. This minor API extension

makes it possible to write ``numerator, denominator =

x.as_integer_ratio()`` and have it work across multiple numeric types.

(Contributed by Lisa Roach in:issue:`33073` and Raymond Hettinger in

:issue:`37819`.)

* Constructors of:class:`int`,:class:`float` and:class:`complex` will now

use the:meth:`~object.__index__` special method, if available and the

never intended to permit more than a bare name on the left-hand side of a

keyword argument assignment term. See:issue:`34641`.

* Iterable unpacking is now allowed without parentheses in:keyword:`yield`

and:keyword:`return` statements.

(Contributed by David Cuthbert and Jordan Chapman in:issue:`32117`.)

* Generalized iterable unpacking in:keyword:`yield` and

:keyword:`return` statements no longer requires enclosing parentheses.

This brings the *yield* and *return* syntax into better agreement with

normal assignment syntax::

(Contributed by Serhiy Storchaka in:issue:`15248`.)

(Contributed by David Cuthbert and Jordan Chapman in:issue:`32117`.)

* When a comma is missed in code such as ``[(10, 20) (30, 40)]``, the

compiler displays a:exc:`SyntaxWarning` with a helpful suggestion.

This improves on just having a:exc:`TypeError` indicating that the

first tuple was not callable. (Contributed by Serhiy Storchaka in

:issue:`15248`.)

* Arithmetic operations between subclasses of:class:`datetime.date` or

:class:`datetime.datetime` and:class:`datetime.timedelta` objects now return

and Windows use this to properly terminate scripts in interactive sessions.

(Contributed by Google via Gregory P. Smith in:issue:`1054041`.)

* Added new ``replace()`` method to the code type (:class:`types.CodeType`).

* Some advanced styles of programming require updating the

:class:`types.CodeType` object for an existing function. Since code

objects are immutable, a new code object needs to be created, one

that is modeled on the existing code object. With 19 parameters,

this was somewhat tedious. Now, the new ``replace()`` method makes

it possible to create a clone with a few altered parameters.

Here's an example that alters the:func:`statistics.mean` function to

prevent the *data* parameter from being used as a keyword argument::

(Contributed by Victor Stinner in:issue:`37032`.)

* For integers, the three-argument form of the:func:`pow` function now

(Contributed by Mark Dickinson in:issue:`36027`.)

* When dictionary comprehensions are evaluated, the key is now evaluated before

the value, as proposed by:pep:`572`.

* Dict comprehensions have been synced-up with dict literals so that the

key is computed first and the value second::

The guaranteed execution order is helpful with assignment expressions

because variables assigned in the key expression will be available in

the value expression::

New Modules

* None yet.

* The new:mod:`importlib.metadata` module provides (provisional) support for

reading metadata from third-party packages. For example, it can extract an

installed package's version number, list of entry points, and more::

(Contributed in:issue:`34632` by Barry Warsaw and Jason R. Coombs.)

Improved Modules