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Remove deprecated sre_* modules #105456
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Activity
Do they have much use in the top 5k PyPI packages?
For example: https://dev.to/hugovk/how-to-search-5000-python-projects-31gk
It is still used, yes.
But, many results here are from mypy / typeshed / jedi usages, which are safe.
There are some string usages, like inisort,pipreqs,ruff, and in onepytestplugin, which are also safe: for example,pytestdoes not recognisesre_*modules as stdlib ones.Notice, that some results are from vendored dependencies that would be quite hard to update.
Full results of
cpython/search_pypi_top.py -q . "sre_(compile|constants|parse)" > results.txt
results.txtReacted by Zhang NaIt's interesting that exrex already uses
re._parser. This project is: "Irregular methods for regular expressions."../exrex-0.11.0.tar.gz: exrex-0.11.0/exrex.py: import re._parser as sre_parse ./exrex-0.11.0.tar.gz: exrex-0.11.0/exrex.py: from re import sre_parseAnother project is using the private
re._constantssub-module (people love to abuse the private API instead of asking to make what they need public):./rstr-3.2.1.tar.gz: rstr-3.2.1/rstr/xeger.py: import re._parser as sre_parse # type: ignore[import] ./rstr-3.2.1.tar.gz: rstr-3.2.1/rstr/xeger.py: import sre_parse # type: ignore[no-redef] ./rstr-3.2.1.tar.gz: rstr-3.2.1/rstr/xeger.py: parsed = sre_parse.parse(pattern)Another example:
./catboost-1.2.tar.gz: catboost-1.2/catboost_all_src/contrib/python/hypothesis/py3/hypothesis/strategies/_internal/regex.py: import re._parser as sre_parsepyparsing was using sre_constants, it's no longer the case:
Version 3.0.8 - April, 2022 --------------------------- (...) - Removed imports of deprecated `sre_constants` module for catching exceptions when compiling regular expressions. PR submitted by Serhiy Storchaka, thank you.There are vendored copies of pyparsing which still use sre_constants.
coverage test suite explicitly ignores the deprecation, tests/conftest.py:
warnings.filterwarnings( "ignore", category=DeprecationWarning, message=r"module 'sre_constants' is deprecated", )
Similar example:
./pydantic_factories-1.17.3.tar.gz: pydantic_factories-1.17.3/CHANGELOG.md: - fix deprecation warning for `sre_parse` on Python 3.11. ./pydantic_factories-1.17.3.tar.gz: pydantic_factories-1.17.3/pydantic_factories/value_generators/regex.py: from sre_parse import SubPattern, parse # pylint: disable=deprecated-moduleor:
./trio-0.22.0.tar.gz: trio-0.22.0/trio/tests/test_exports.py: "ignore:module 'sre_constants' is deprecated:DeprecationWarning",I would prefer that people don't use private APIs. But well, as soon as it's technically possible, people just continue to do that.
Do they have much use in the top 5k PyPI packages?
At the least, it's unclear to me if it's ok or not to remove these modules right now. I would say that it's ok since we respected PEP 387 deprecation period. But @serhiy-storchaka may have a different opinion.
Initially I was going to not keep old modules. But it was shown that they are used in some third-party projects, so it would be nicer from us to keep them for a time. Now we can remove them at any time. But it would be even more nicer if we first add public API for things used in third-party code. It is not always feasible, for example
re._constantsis inherently implementation detail. But I was going to add public API for compiling replacement strings.Reacted by sobolevnSearching the top (500) pypi projects I find that the only concerning use is from isort. In general it seems most projects use the re modules.
How about we hard deprecate for 3.16?
How about we hard deprecate for 3.16?
What do you mean by hard deprecation? For example, sre_constants already emits a
DeprecationWarning:$ python3.13 -Wd -c 'import sre_constants' <string>:1: DeprecationWarning: module 'sre_constants' is deprecatedWhat do you mean by hard deprecation?
From my understanding it is moving it from the deprecated stage to the pending removal in a defined version stage, i.e.
$ python3.15 -Wd -c 'import sre_constants' <string>:1: DeprecationWarning: module 'sre_constants' is deprecated and will be removed in 3.16Alright, I see that the 3
sremodules are listed in "Pending removal in future versions", so no scheduled version: https://docs.python.org/dev/whatsnew/3.14.html#pending-removal-in-future-versionsScheduling the removal in a specific version should help users to decide when to handle these deprecations.
Reacted by Stan UlbrychI will write a PR setting it to 3.16 unless you prefer a later version, it has been long enough IMO?
Searching the top (500) pypi projects I find that the only concerning use is from isort.
This use is fine, isort has lists of known modules in each Python version.
Scheduling the removal in a specific version should help users to decide when to handle these deprecations.
Yep, we could even remove them now, but @serhiy-storchaka was planning to add some public API: #105456 (comment). Any news?
See #135992.
It is good tone to only break the old way if the new way exists in few versions. But since
sre_*modules were undocumented and they have been deprecated for several versions, we can remove them now.Reacted by Stan Ulbrych- added a commit that references this issue
on Jul 1, 2025
Feature or enhancement
sre_*modules likesre_constants,sre_compile, andsre_parsewere deprecated in3.11in 1be3260Our regular deprecation policy is that the deprecated things can be removed in N + 2 release, which is
3.13.Pitch
Let's remove them if there are no objections.
I guess it is safe to remove them for several reasons:
re._parser,re._constants, andre._compilermodules that are used insteadThe only argument agaist removing them:
I will send a PR once we settle it:
@vstinner @serhiy-storchaka what's your opinion?
Linked PRs
sre_*modules #135994