Issues

• re.search() misses matches when a pattern starts with a scoped (?a:...) or (?u:...) group

  stdlibtopic-regextype-bug
  python/cpython#158374 · Filter by author BwL1289 opened on Sep 29, 2026
  2

• re.finditer() leaks reference cycles through its input

  extension-modulestopic-regextype-bug
  python/cpython#158095 · Filter by author YangSiJun528 opened on Sep 24, 2026

• A backreference does not match characters which are matched case-insensitively as literals

  stdlibtopic-regextype-bug
  python/cpython#156513 · Filter by author serhiy-storchaka opened on Aug 28, 2026

• \p{...} names ignore only spaces, though the docs promise whitespace

  3.16stdlibtopic-regextype-bug
  python/cpython#156185 · Filter by author fedonman opened on Aug 21, 2026
  1

  

• \p{Alphabetic} matches gc=L, not the Unicode Alphabetic property

  stdlibtopic-regextype-bug
  python/cpython#155498 · Filter by author fedonman opened on Aug 10, 2026
  1

  

• \p{...} gives wrong results when mixed with letters under re.IGNORECASE

  extension-modulestopic-regextype-bug
  python/cpython#155297 · Filter by author lkk7 opened on Aug 6, 2026
  1

  

• Deprecate re.LOCALE

  stdlibtopic-regextype-feature
  python/cpython#153177 · Filter by author serhiy-storchaka opened on Jul 6, 2026

• Look through group marks in the regex alternation quick check

  performancestdlibtopic-regextype-feature
  python/cpython#153169 · Filter by author serhiy-storchaka opened on Jul 6, 2026
  2

• Cache the match object in the compiled re pattern

  performancestdlibtopic-regextype-feature
  python/cpython#153161 · Filter by author serhiy-storchaka opened on Jul 6, 2026
  3

• Auto-possessify greedy repeats in regular expressions

  performancestdlibtopic-regextype-feature
  python/cpython#153044 · Filter by author serhiy-storchaka opened on Jul 4, 2026
  7

• Support set operations in regular expression character classes

  stdlibtopic-regextype-feature
  python/cpython#152100 · Filter by author serhiy-storchaka opened on Jun 24, 2026

• Speed up matching of case-insensitive character sets

  performancestdlibtopic-regextype-feature
  python/cpython#152054 · Filter by author eendebakpt opened on Jun 24, 2026
  1

• Support redefinition of named capture groups in regular expressions

  extension-modulestopic-regextype-feature
  python/cpython#152026 · Filter by author serhiy-storchaka opened on Jun 23, 2026
  3

• Improve performance of re.compile() for patterns with character ranges

  performancestdlibtopic-regextype-feature
  python/cpython#149427 · Filter by author eendebakpt opened on May 5, 2026

• Speed up multiline regexes anchored by ^.

  extension-modulesperformancetopic-regextype-feature
  python/cpython#148762 · Filter by author haampie opened on Apr 19, 2026
  6

• Use memchr in SRE's prefix scanner

  extension-modulesperformancetopic-regextype-feature
  python/cpython#148729 · Filter by author haampie opened on Apr 18, 2026
  8

• re.sub() repl notation explanation is disjointed

  docstopic-regex
  python/cpython#144884 · Filter by author cben opened on Feb 16, 2026

• Buggy or strange behaviour matching mutable data with re

  extension-modulestopic-regextype-bug
  python/cpython#143516 · Filter by author petersuttondev opened on Jan 7, 2026
  3

• Add Lookbehind Assertions doc

  docstopic-regex
  python/cpython#136618 · Filter by author alex-semenyuk opened on Jul 13, 2025

• Make re.Match a well-rounded Sequence type

  extension-modulestopic-regextype-feature
  python/cpython#133546 · Filter by author vberlier opened on May 7, 2025
  5

• Escaping the repl argument to re.sub(), re.subn()

  docstopic-regex
  python/cpython#128138 · Filter by author finite-state-machine opened on Dec 20, 2024
  2

• Refactor - remove re._compile?

  stdlibtopic-regextype-feature
  python/cpython#122358 · Filter by author wimglenn opened on Jul 27, 2024
  5

• Provide improved error message for regex parse failures

  stdlibtopic-regextype-feature
  python/cpython#116425 · Filter by author jhance opened on Mar 6, 2024
  1

• Top-level functions of re.module should support the string indexing pos/endpos arguments

  topic-regextype-feature
  python/cpython#113304 · Filter by author adamsilkey opened on Dec 20, 2023
  5

• Ability to query minimum and maxium length of regular expression

  stdlibtopic-regextype-feature
  python/cpython#112386 · Filter by author MegaIng opened on Nov 24, 2023
  2