https://github.com/python/cpython/commit/a7abb8c8e6970f01d12c34d956b2cc9d31a41235 commit: a7abb8c8e6970f01d12c34d956b2cc9d31a41235 branch: 3.14 author: Miss Islington (bot) <31488909+miss-isling...@users.noreply.github.com> committer: ZeroIntensity <zintensity...@gmail.com> date: 2025-06-19T15:07:12Z summary:
[3.14] Docs: Add missing lines between regex and text (GH-134505) (GH-135718) Docs: Add missing lines between regex and text (GH-134505) (cherry picked from commit 754190287ece5a2e66684161aadafb18f5f44868) Co-authored-by: Rafael Fontenelle <rffontene...@users.noreply.github.com> files: M Doc/howto/regex.rst diff --git a/Doc/howto/regex.rst b/Doc/howto/regex.rst index e543f6d5657d79..7486a378dbb06f 100644 --- a/Doc/howto/regex.rst +++ b/Doc/howto/regex.rst @@ -1016,7 +1016,9 @@ extension. This regular expression matches ``foo.bar`` and Now, consider complicating the problem a bit; what if you want to match filenames where the extension is not ``bat``? Some incorrect attempts: -``.*[.][^b].*$`` The first attempt above tries to exclude ``bat`` by requiring +``.*[.][^b].*$`` + +The first attempt above tries to exclude ``bat`` by requiring that the first character of the extension is not a ``b``. This is wrong, because the pattern also doesn't match ``foo.bar``. @@ -1043,7 +1045,9 @@ confusing. A negative lookahead cuts through all this confusion: -``.*[.](?!bat$)[^.]*$`` The negative lookahead means: if the expression ``bat`` +``.*[.](?!bat$)[^.]*$`` + +The negative lookahead means: if the expression ``bat`` doesn't match at this point, try the rest of the pattern; if ``bat$`` does match, the whole pattern will fail. The trailing ``$`` is required to ensure that something like ``sample.batch``, where the extension only starts with _______________________________________________ Python-checkins mailing list -- python-checkins@python.org To unsubscribe send an email to python-checkins-le...@python.org https://mail.python.org/mailman3//lists/python-checkins.python.org Member address: arch...@mail-archive.com
