Skip to content
2 changes: 1 addition & 1 deletion developer-workflow/index.rst
Original file line number Diff line number Diff line change
Expand Up @@ -8,11 +8,11 @@ Development workflow
:maxdepth: 5

communication-channels
lang-changes
development-cycle
stdlib
extension-modules
c-api
lang-changes
grammar
porting
sbom
Expand Down
178 changes: 127 additions & 51 deletions developer-workflow/lang-changes.rst
Original file line number Diff line number Diff line change
@@ -1,37 +1,42 @@
.. _lang-changes:
.. _langchanges:

Changing the Python language
============================
On occasion people come up with an idea on how to change or improve Python as a
programming language. This document is meant to explain exactly what changes
have a reasonable chance of being considered and what the process is to propose
changes to the language.
Changing Python
===============

On occasion people come up with an idea for changing or improving Python.
This page explains how to explore change proposals and what changes
have a reasonable chance of being considered.

What qualifies

Considerations
--------------
First and foremost, it must be understood that changes to the Python
programming language are difficult to make. When the language changes,
**every** Python programmer already in existence and all Python programmers to

First, understand that changes to Python
are difficult to make. When the language changes,
**every** Python programmer and all Python programmers to
come will end up eventually learning about the change you want to propose.
Books will need updating, code will be changed, and a new way to do things will
need to be learned. Changes to the Python programming language are never taken
need to be learned. Changes to Python are never taken
lightly.

Because of the seriousness that language changes carry, any change must be
beneficial to a large proportion of Python users. If the change only benefits a
small percentage of Python developers then the change will not be made. A good
way to see if your idea would work for a large portion of the Python community
is to ask in the `Ideas Discourse category`_. You can also
go through Python's stdlib and find examples of code which would benefit from
your proposed change (which helps communicate the usefulness of your change to
others). For further guidance, see :ref:`suggesting-changes`.
Backward compatibility is a significant concern. Existing Python code has to
continue to work. There are exceptions to this rule, but they are very rare
and are only allowed when the benefits of the change greatly outweigh the costs
of breaking existing code.

Your proposed change also needs to be *Pythonic*. While only the Steering
Council can truly classify something as Pythonic, you can read the
:pep:`Zen of Python <20>` for guidance.
Because of the seriousness of changing the language, any change must be
beneficial to many Python users. If the change only helps a small percentage of
Python developers then the change will not be made. A good way to see if your
idea would work for a large portion of the Python community is to discuss it in
the `Ideas Discourse category <ideas_>`_. You can also look in Python's standard
library to find examples of code which would benefit from your proposed change.

.. important::
For all of these reasons, most proposed changes to Python are rejected. This
doesn't mean you shouldn't suggest them. It can be useful to explore
alternatives and to get feedback from the community. Just be aware that
getting a change accepted is difficult. Don't take it personally.

.. index::
single: PEP process
Expand All @@ -41,25 +46,98 @@ Council can truly classify something as Pythonic, you can read the
Suggesting new features and language changes
--------------------------------------------

The `Ideas Discourse category`_
is specifically intended for discussion of new features and language changes.
Please don't be disappointed if your idea isn't met with universal approval:
as the :pep:`long list of Withdrawn and Rejected PEPs
<0#rejected-superseded-and-withdrawn-peps>`
in the :pep:`PEP Index <0>` attests,
and as befits a reasonably mature programming language,
getting significant changes into Python isn't a simple task.
Proposing a change involves the following steps:

- Describe your idea in detail.

- Engage in discussion about the idea.

- Rarely, the idea will advance to a formal proposal stage.


Describe your idea
^^^^^^^^^^^^^^^^^^

The `Ideas Discourse category <ideas_>`_ is specifically intended for discussion
of new features and language changes. Make your proposal as a `new topic
<ideas_>`_ there.

Your proposal needs to be **detailed**. Describe the change you want to make,
why you want to make it, and what benefits it will bring to Python users. Be
specific. Show that you have considered the effect of the change on existing
code.

Some things you should **not** do:

- **Don't** format your idea as a Python Enhancement Proposal (*PEP*).
It's good to use the PEP template as a
guide for what information to include, but don't try to write a full PEP
until the idea has been accepted for further consideration.
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Perhaps also add here that keeping the proposal short makes it far more likely that people will actually read it?

Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I'm not sure how best to describe the right balance between brevity and detail.

Copy link
Member

@AA-Turner AA-Turner Oct 19, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

As a starter for ten?:

"Ensure your description covers all the salient points of the proposal, and make it as short as possible, but no shorter. This maximises the liklihood that other members of the community will have the time to read and consider your proposal, and is a considerate way to be respectful of their time"

Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I added a bullet to the "Do" list about balancing brevity and detail.


- **Don't** create a list of proposed changes. Each idea needs its own
discussion. Proposing a change is significant work. You will need to spend
time on each proposal. A tossed-off list will not be taken seriously.

When justifying your idea, these are not good reasons to make a change:

- "Other languages work this way." Languages are different. What works well
in one language may not work well in Python, or Python may already have a
way to do a similar thing.

- "It would be nice." This is too vague. Be specific about the benefits
your change will bring, and consider the costs as well.

Some things you **should** do:

- Research whether your idea has been proposed before. There are many
suggestions that have been made and rejected in the past. If your idea has a
history, read the discussion to see why it was rejected. Previously rejected
ideas are especially unlikely to get accepted. If you can address the
concerns raised in the previous discussion, mention that in your proposal.

- Read other ideas to see how they are presented. This will help you flesh out
your proposal.

- Read other ideas to understand the kinds of concerns that are raised and
objections that must be answered. Your proposal will be stronger if you can
address these concerns up front.


Engage in discussion
^^^^^^^^^^^^^^^^^^^^

Once you post your proposal, people will respond. You need to continue
the discussion, answer questions, and address objections. This is an important
part of the process. Other people's perspectives will help explore the full
impact of the idea and find strengths or weaknesses you may not have
considered.

You will almost always get at least some push-back. Don't be disappointed, and don't take it personally.
As the long list of :pep:`Withdrawn and Rejected PEPs
<0#rejected-superseded-and-withdrawn-peps>` in the :pep:`PEP Index <0>`
attests, and as befits a mature programming language, getting significant
changes into Python isn't a simple task.

Engage in good faith. The goal of the discussion is to find the best balance
between competing concerns. If your idea has merit, the discussion will help
refine it and make it stronger. If your idea has flaws, the discussion will
help identify them so you can address them or move on. Keep the discussion
productive and focused on the issues, not on personalities.

It's especially useful to get core team members involved in the discussion.
Sometimes they will differ in opinion, or merely be unconvinced. When there
isn't a clear positive sentiment, the `Status Quo Wins a Stalemate`_.

Even if your idea is not accepted, the discussion can help you and others
understand the design of Python better, and help inform future proposals.

If the idea is reasonable, someone will suggest posting it as a feature
request on the `issue tracker`_, or, for larger changes,
writing it up as PEP following the :ref:`lang-changes-pep-process`.

Sometimes core developers will differ in opinion,
or merely be collectively unconvinced.
When there isn't an obvious victor, then the `Status Quo Wins a Stalemate`_.
Formal proposal
^^^^^^^^^^^^^^^

For some examples on language changes that were accepted,
see `Justifying Python Language Changes`_.
If the idea gets positive discussion, someone will suggest posting it as a
feature request on the `issue tracker`_, or, for larger changes, writing it up
as PEP following the :ref:`lang-changes-pep-process`. Congratulations!


.. index:: PEP process
Expand All @@ -69,20 +147,18 @@ see `Justifying Python Language Changes`_.
PEP process
-----------

Once you are certain you have a language change proposal
which will appeal to the general Python community,
you can begin the :abbr:`PEP (Python enhancement proposal)` process
to officially propose the change.
See :pep:`1` for information on PEPs and the PEP process,
and the :pep:`PEP Index <0>` for examples.
Once you are certain you have a language change proposal which will appeal to
the general Python community, you can begin the :abbr:`PEP (Python enhancement
proposal)` process to officially propose the change. See :pep:`1` for
information on PEPs and the PEP process, and the :pep:`PEP Index <0>` for
examples.

If the PEP is accepted, then your proposed language change will be introduced
in the next release of Python.
Otherwise, your PEP will be recorded as rejected along with an explanation,
to inform others who may propose a similar language change in the future.
If the PEP is accepted, then your language change will be introduced in a
future release of Python. Otherwise, your PEP will be recorded as rejected
along with an explanation, to inform others who may propose a similar language
change in the future.


.. _issue tracker: https://github.com/python/cpython/issues
.. _Ideas Discourse category: https://discuss.python.org/c/ideas/6
.. _Status Quo Wins a Stalemate: https://www.curiousefficiency.org/posts/2011/02/status-quo-wins-stalemate.html
.. _Justifying Python Language Changes: https://www.curiousefficiency.org/posts/2011/02/justifying-python-language-changes.html
.. _ideas: https://discuss.python.org/c/ideas/6
.. _Status Quo Wins a Stalemate: https://www.curiousefficiency.org/posts/2011/02/status-quo-wins-stalemate/
Loading