diff options
| -rw-r--r-- | Doc/library/re.rst | 7 | ||||
| -rw-r--r-- | Doc/whatsnew/3.14.rst | 4 | ||||
| -rw-r--r-- | Lib/test/test_re.py | 13 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Library/2024-11-19-10-46-57.gh-issue-124130.OZ_vR5.rst | 4 | ||||
| -rw-r--r-- | Modules/_sre/sre_lib.h | 12 |
5 files changed, 15 insertions, 25 deletions
diff --git a/Doc/library/re.rst b/Doc/library/re.rst index 9db6f1d..29387a4 100644 --- a/Doc/library/re.rst +++ b/Doc/library/re.rst @@ -572,11 +572,8 @@ character ``'$'``. Word boundaries are determined by the current locale if the :py:const:`~re.LOCALE` flag is used. - .. note:: - - Note that ``\B`` does not match an empty string, which differs from - RE implementations in other programming languages such as Perl. - This behavior is kept for compatibility reasons. + .. versionchanged:: next + ``\B`` now matches empty input string. .. index:: single: \d; in regular expressions diff --git a/Doc/whatsnew/3.14.rst b/Doc/whatsnew/3.14.rst index 4b3f1b2..61f5ffd 100644 --- a/Doc/whatsnew/3.14.rst +++ b/Doc/whatsnew/3.14.rst @@ -245,6 +245,10 @@ Other language changes making it a :term:`generic type`. (Contributed by Brian Schubert in :gh:`126012`.) +* ``\B`` in :mod:`regular expression <re>` now matches empty input string. + Now it is always the opposite of ``\b``. + (Contributed by Serhiy Storchaka in :gh:`124130`.) + * iOS and macOS apps can now be configured to redirect ``stdout`` and ``stderr`` content to the system log. (Contributed by Russell Keith-Magee in :gh:`127592`.) diff --git a/Lib/test/test_re.py b/Lib/test/test_re.py index 0d3599b..5538de6 100644 --- a/Lib/test/test_re.py +++ b/Lib/test/test_re.py @@ -978,18 +978,15 @@ class ReTests(unittest.TestCase): self.assertIsNone(re.fullmatch(br".+\B", b"abc", re.LOCALE)) self.assertIsNone(re.fullmatch(r".+\B", "ьюя")) self.assertTrue(re.fullmatch(r".+\B", "ьюя", re.ASCII)) - # However, an empty string contains no word boundaries, and also no - # non-boundaries. + # However, an empty string contains no word boundaries. self.assertIsNone(re.search(r"\b", "")) self.assertIsNone(re.search(r"\b", "", re.ASCII)) self.assertIsNone(re.search(br"\b", b"")) self.assertIsNone(re.search(br"\b", b"", re.LOCALE)) - # This one is questionable and different from the perlre behaviour, - # but describes current behavior. - self.assertIsNone(re.search(r"\B", "")) - self.assertIsNone(re.search(r"\B", "", re.ASCII)) - self.assertIsNone(re.search(br"\B", b"")) - self.assertIsNone(re.search(br"\B", b"", re.LOCALE)) + self.assertTrue(re.search(r"\B", "")) + self.assertTrue(re.search(r"\B", "", re.ASCII)) + self.assertTrue(re.search(br"\B", b"")) + self.assertTrue(re.search(br"\B", b"", re.LOCALE)) # A single word-character string has two boundaries, but no # non-boundary gaps. self.assertEqual(len(re.findall(r"\b", "a")), 2) diff --git a/Misc/NEWS.d/next/Library/2024-11-19-10-46-57.gh-issue-124130.OZ_vR5.rst b/Misc/NEWS.d/next/Library/2024-11-19-10-46-57.gh-issue-124130.OZ_vR5.rst new file mode 100644 index 0000000..a1d4fc8 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2024-11-19-10-46-57.gh-issue-124130.OZ_vR5.rst @@ -0,0 +1,4 @@ +Fix a bug in matching regular expression ``\B`` in empty input string. +Now it is always the opposite of ``\b``. +To get an old behavior, use ``(?!\A\Z)\B``. +To get a new behavior in old Python versions, use ``(?!\b)``. diff --git a/Modules/_sre/sre_lib.h b/Modules/_sre/sre_lib.h index af4bfc5..df37790 100644 --- a/Modules/_sre/sre_lib.h +++ b/Modules/_sre/sre_lib.h @@ -42,8 +42,6 @@ SRE(at)(SRE_STATE* state, const SRE_CHAR* ptr, SRE_CODE at) return ((void*) ptr == state->end); case SRE_AT_BOUNDARY: - if (state->beginning == state->end) - return 0; thatp = ((void*) ptr > state->beginning) ? SRE_IS_WORD((int) ptr[-1]) : 0; thisp = ((void*) ptr < state->end) ? @@ -51,8 +49,6 @@ SRE(at)(SRE_STATE* state, const SRE_CHAR* ptr, SRE_CODE at) return thisp != thatp; case SRE_AT_NON_BOUNDARY: - if (state->beginning == state->end) - return 0; thatp = ((void*) ptr > state->beginning) ? SRE_IS_WORD((int) ptr[-1]) : 0; thisp = ((void*) ptr < state->end) ? @@ -60,8 +56,6 @@ SRE(at)(SRE_STATE* state, const SRE_CHAR* ptr, SRE_CODE at) return thisp == thatp; case SRE_AT_LOC_BOUNDARY: - if (state->beginning == state->end) - return 0; thatp = ((void*) ptr > state->beginning) ? SRE_LOC_IS_WORD((int) ptr[-1]) : 0; thisp = ((void*) ptr < state->end) ? @@ -69,8 +63,6 @@ SRE(at)(SRE_STATE* state, const SRE_CHAR* ptr, SRE_CODE at) return thisp != thatp; case SRE_AT_LOC_NON_BOUNDARY: - if (state->beginning == state->end) - return 0; thatp = ((void*) ptr > state->beginning) ? SRE_LOC_IS_WORD((int) ptr[-1]) : 0; thisp = ((void*) ptr < state->end) ? @@ -78,8 +70,6 @@ SRE(at)(SRE_STATE* state, const SRE_CHAR* ptr, SRE_CODE at) return thisp == thatp; case SRE_AT_UNI_BOUNDARY: - if (state->beginning == state->end) - return 0; thatp = ((void*) ptr > state->beginning) ? SRE_UNI_IS_WORD((int) ptr[-1]) : 0; thisp = ((void*) ptr < state->end) ? @@ -87,8 +77,6 @@ SRE(at)(SRE_STATE* state, const SRE_CHAR* ptr, SRE_CODE at) return thisp != thatp; case SRE_AT_UNI_NON_BOUNDARY: - if (state->beginning == state->end) - return 0; thatp = ((void*) ptr > state->beginning) ? SRE_UNI_IS_WORD((int) ptr[-1]) : 0; thisp = ((void*) ptr < state->end) ? |