Draft PEP: imath --- module for number-theoretic functions by skirpichev · Pull Request #8 · skirpichev/peps

skirpichev · 2025-05-10T17:17:48Z

No description provided.

skirpichev · 2025-05-11T13:36:46Z

@vstinner, some major rewrite proposed in #9. Let me know if you more like that version.

vstinner · 2025-05-11T16:40:34Z

+
+Unless we can just provide bindings to some well supported mathematical
+library like the GMP, the module scope should be limited.  For example, no
+primality testing and factorization.


Thank you :-) IMO primality testing is a can a worm and a bad idea for the stdlib :-(

That was just a first example coming in my mind.

I think it's a good idea to show some border line. For the math/cmath modules we have the C standard to reject new stuff. Here it's less obvious.

vstinner · 2025-05-11T16:47:15Z

@vstinner, some major rewrite proposed in #9. Let me know if you more like that version.

I like this version (PR #8).

skirpichev · 2025-05-11T18:04:05Z

@NeilGirdhar, per Victor's opinion I'll prefer to defer major rewriting in #9. Some parts, on which it seems we agree - are ported.

If you are ok with this - I'll add you as co-author and create a pr against the peps repo. Or add you to Acknowledgements section.

NeilGirdhar · 2025-05-11T19:24:29Z

I think the other one reads better (in terms of syntax and grammar, etc.) Since we agree on everything else, why don't we just get rid of the section you don't like in the other one and submit #9?

itamaro · 2025-05-12T01:44:54Z

+There is already an ``imath`` project on PyPI, but only with two releases, with
+the most recent one 4 years ago.  Its repository is no longer accessible.


the pypi project may be abandoned, but this Imath is maintained and fairly active.
Naive code search across my employer's repo has hundreds of hits referring to that imath.
could you consider going with a different name please? :)

I appreciate options. Current version is a compromise, based on the poll. As you could see, I'm in a tiny camp of "something else". My initial proposal was "ntheory" (it also has a dead toy project on PyPI).

I would guess, that words like "random" or "fractions" have even more hits. BTW, linked project seems unrelated to the Python ecosystem.

BTW, linked project seems unrelated to the Python ecosystem.

What do you mean by "unrelated"? It's a C++ library with Python bindings!

Hmm, indeed. Though, as naming is still in the "Open Issues", I wouldn't care too much right now.

@vstinner, what do you think if we start from the "ntheory" variant?

skirpichev · 2025-05-12T06:46:13Z

@NeilGirdhar, I opened python#4422

It looks we fail to reach a consensus on #9, while sponsor seems ok with the current version. So I added you to "Thanks" section so far.

vstinner · 2025-05-12T09:06:30Z

I suppose that this PR can be closed since python#4422 was created.

NeilGirdhar · 2025-05-12T09:21:03Z

It looks we fail to reach a consensus on #9, while sponsor seems ok with the current version. So I added you to "Thanks" section so far.

Could you at least fix all of the grammatical errors?

vstinner · 2025-05-12T09:25:01Z

Could you at least fix all of the grammatical errors?

Would you mind to write a review on python#4422 ?

StanFromIreland · 2025-05-12T16:04:08Z

+Type: Standards Track
+Created: 10-May-2025
+Python-Version: 3.15
+Post-History: 02-Jun-2019,


Is there no link to the thread?

StanFromIreland · 2025-05-12T16:05:10Z

+to the mathematical functions defined by the C standard."  But as a state of
+art, over time the module was populated with functions that aren't related to


It should be state of the art

StanFromIreland · 2025-05-12T16:05:31Z

+The :external+py3.14:mod:`math` documentation says: "This module provides access
+to the mathematical functions defined by the C standard."  But as a state of
+art, over time the module was populated with functions that aren't related to
+the C standard or floating-point arithmetics.  Now it's much harder to describe


Typo, it should be singular.

StanFromIreland · 2025-05-12T16:05:58Z

+module scope, content and interfaces (returned values or accepted arguments).
+
+For example, the :external+py3.14:mod:`math` module documentation says: "Except
+when explicitly noted otherwise, all return values are floats."  This is not


This is no longer true...

StanFromIreland · 2025-05-12T16:06:33Z

+For example, the :external+py3.14:mod:`math` module documentation says: "Except
+when explicitly noted otherwise, all return values are floats."  This is not
+longer true:  *None* of the functions listed in the "Number-theoretic
+functions" [1]_ subsection of the documentation returns a float, but the


IMO it should be return

StanFromIreland · 2025-05-12T16:07:19Z

+longer true:  *None* of the functions listed in the "Number-theoretic
+functions" [1]_ subsection of the documentation returns a float, but the
+documentation doesn't say so.  In the proposed module a similar sentence "All
+return values are integers." could tell the truth once.  In a similar way we


How about would consistently reflect reality. The current one is a bit awkward.

StanFromIreland · 2025-05-12T16:08:00Z

+functions" [1]_ subsection of the documentation returns a float, but the
+documentation doesn't say so.  In the proposed module a similar sentence "All
+return values are integers." could tell the truth once.  In a similar way we
+can simplify description of accepted arguments for both the


simplify the description of accepted arguments

StanFromIreland · 2025-05-12T16:08:37Z

+can simplify description of accepted arguments for both the
+:external+py3.14:mod:`math` and the new module.
+
+Apparently, the :external+py3.14:mod:`math` can't serve as a catch-all place


the :external+py3.14:mod:math module can't serve

StanFromIreland · 2025-05-12T16:09:15Z

+:external+py3.14:mod:`math` and the new module.
+
+Apparently, the :external+py3.14:mod:`math` can't serve as a catch-all place
+for mathematical functions: we have also the :external+py3.14:mod:`cmath` and


we also have the

StanFromIreland · 2025-05-12T16:09:39Z

+
+Apparently, the :external+py3.14:mod:`math` can't serve as a catch-all place
+for mathematical functions: we have also the :external+py3.14:mod:`cmath` and
+the :external+py3.14:mod:`statistics`.  Let's make same for integer-related


Let's do the same

StanFromIreland · 2025-05-12T16:10:37Z

+Specification
+=============
+
+The PEP proposes moving the following integer-related functions [1]_ in a new


functions [1]_ to a new

Sorry I cannot do suggestions, the button is not there and otherwise this is more efficient.

StanFromIreland · 2025-05-12T16:11:04Z

+
+Their aliases in :external+py3.14:mod:`math` will be :term:`soft deprecated`.
+
+Modules functions will accept integers and objects that implement the


Singular, Module

StanFromIreland · 2025-05-12T16:11:28Z

+:external+py3.14:meth:`~object.__index__` method which is used to convert the
+object to an integer number.
+
+Possible extensions for the new module and it's scope are discussed in the


Possible extensions to the

StanFromIreland · 2025-05-12T16:12:05Z

+object to an integer number.
+
+Possible extensions for the new module and it's scope are discussed in the
+`Open Issues <Open Issues_>`_ section.  New functions are not part of the


New functions are not part of this Clearer for here IMO

StanFromIreland · 2025-05-12T16:12:44Z

+Module name
+-----------
+
+Chosen name seems consistent with other domain-specific mathematical module:


The chosen name

StanFromIreland · 2025-05-12T16:13:00Z

+Backwards Compatibility
+=======================
+
+As aliases in :external+py3.14:mod:`math` will be kept for indefinite time


will be kept for an indefinite time

serhiy-storchaka · 2025-05-12T16:13:14Z

@StanFromIreland, please use "Start a review" instead of "Add single comment" and publish all your comments at once. The difference is that other people will get one email message instead of an message per comment.

StanFromIreland · 2025-05-12T16:13:32Z

+Reference Implementation
+========================
+
+https://github.com/python/cpython/pull/133909


This should be styled better.

StanFromIreland · 2025-05-12T16:13:57Z

+Module name
+-----------
+
+Chosen name seems consistent with other domain-specific mathematical module:


StanFromIreland · 2025-05-12T16:14:23Z

+Chosen name seems consistent with other domain-specific mathematical module:
+:external+py3.14:mod:`cmath` (for complex numbers).
+
+There is already an ``imath`` project on PyPI, but only with two releases, with


Can we have a link?

StanFromIreland · 2025-05-12T16:14:47Z

+:external+py3.14:mod:`cmath` (for complex numbers).
+
+There is already an ``imath`` project on PyPI, but only with two releases, with
+the most recent one 4 years ago.  Its repository is no longer accessible.


StanFromIreland · 2025-05-12T16:15:07Z

+There is already an ``imath`` project on PyPI, but only with two releases, with
+the most recent one 4 years ago.  Its repository is no longer accessible.
+The `Imath <https://github.com/AcademySoftwareFoundation/Imath>`_ C++ library
+include Python bindings with same name.


StanFromIreland · 2025-05-12T16:15:54Z

+There is already an ``imath`` project on PyPI, but only with two releases, with
+the most recent one 4 years ago.  Its repository is no longer accessible.
+The `Imath <https://github.com/AcademySoftwareFoundation/Imath>`_ C++ library
+include Python bindings with same name.


with the same names.

I should have opened pr against this branch instead of my spew of suggestions, apologies.

StanFromIreland · 2025-05-12T16:16:44Z

+with any PyPI module.  On the other hand, ``intmath`` may be confused with
+interval math or numerical integration.
+
+Other proposed names include ``ntheory`` (like SymPy's submodule),


Maybe this is better in the past tense now?

Other proposed names included

vstinner · 2025-05-12T16:20:40Z

@StanFromIreland: You reviewed a closed PR. You should review python#4422 instead.

StanFromIreland · 2025-05-12T16:22:35Z

Yes, I had not refreshed and missed it… oops.

Draft PEP: imath --- module for number-theoretic functions

ff31e7d

skirpichev mentioned this pull request May 10, 2025

Draft PEP: imath --- module for number-theoretic functions #6

Merged

skirpichev force-pushed the main branch from 09db98e to 166ddce Compare May 11, 2025 03:37

vstinner reviewed May 11, 2025

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Comment thread peps/pep-9999.rst Outdated

Comment thread peps/pep-9999.rst Outdated

skirpichev added 3 commits May 11, 2025 16:20

address sponsor review and cherry-pick few things from #9

e52a149

Oh, and fill that)

593eccd

+1

931a7ca

serhiy-storchaka reviewed May 11, 2025

View reviewed changes

Comment thread peps/pep-9999.rst Outdated

vstinner reviewed May 11, 2025

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skirpichev added 2 commits May 11, 2025 20:15

Address reviews

8a2b53d

port some stuff from #9

5986156

vstinner reviewed May 11, 2025

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Comment thread peps/pep-9999.rst

vstinner mentioned this pull request May 11, 2025

gh-81313: Add the math.integer module (PEP-791) python/cpython#133909

Merged

itamaro reviewed May 12, 2025

View reviewed changes

skirpichev added 10 commits May 12, 2025 06:04

address review: link to the poll

e3a9893

link to implementation

643a817

address review: naming consistency

e6f7e5d

+ email

bc118fb

Mention conflict with Imath

07b4103

expand Specification

4756481

expand abstract

5cbccf7

slightly expand "Motivation" section to avoid (I hope) "Rationale"

ebdb7b4

+Acknowledgements

03363dd

+ typos

1a36f63

skirpichev closed this May 12, 2025

skirpichev deleted the imath branch May 12, 2025 10:29

StanFromIreland reviewed May 12, 2025

View reviewed changes

		There is already an ``imath`` project on PyPI, but only with two releases, with
		the most recent one 4 years ago. Its repository is no longer accessible.

		to the mathematical functions defined by the C standard." But as a state of
		art, over time the module was populated with functions that aren't related to


		Their aliases in :external+py3.14:mod:`math` will be :term:`soft deprecated`.

		Modules functions will accept integers and objects that implement the

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skirpichev commented May 10, 2025

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skirpichev commented May 11, 2025 •

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