https://github.com/python/cpython/commit/9b7294c3a560f43f1e26a0f48c258829076d6464 commit: 9b7294c3a560f43f1e26a0f48c258829076d6464 branch: main author: Barney Gale <[email protected]> committer: barneygale <[email protected]> date: 2024-11-04T19:29:57Z summary:
GH-126363: Speed up pattern parsing in `pathlib.Path.glob()` (#126364) The implementation of `Path.glob()` does rather a hacky thing: it calls `self.with_segments()` to convert the given pattern to a `Path` object, and then peeks at the private `_raw_path` attribute to see if pathlib removed a trailing slash from the pattern. In this patch, we make `glob()` use a new `_parse_pattern()` classmethod that splits the pattern into parts while preserving information about any trailing slash. This skips the cost of creating a `Path` object, and avoids some path anchor normalization, which makes `Path.glob()` slightly faster. But mostly it's about making the code less naughty. Co-authored-by: Tomas R. <[email protected]> files: A Misc/NEWS.d/next/Library/2024-11-03-14-43-51.gh-issue-126363.Xus7vU.rst M Lib/pathlib/_local.py diff --git a/Lib/pathlib/_local.py b/Lib/pathlib/_local.py index ef072b83d96904..99474e1f71a307 100644 --- a/Lib/pathlib/_local.py +++ b/Lib/pathlib/_local.py @@ -274,6 +274,31 @@ def _parse_path(cls, path): root = sep return drv, root, [x for x in rel.split(sep) if x and x != '.'] + @classmethod + def _parse_pattern(cls, pattern): + """Parse a glob pattern to a list of parts. This is much like + _parse_path, except: + + - Rather than normalizing and returning the drive and root, we raise + NotImplementedError if either are present. + - If the path has no real parts, we raise ValueError. + - If the path ends in a slash, then a final empty part is added. + """ + drv, root, rel = cls.parser.splitroot(pattern) + if root or drv: + raise NotImplementedError("Non-relative patterns are unsupported") + sep = cls.parser.sep + altsep = cls.parser.altsep + if altsep: + rel = rel.replace(altsep, sep) + parts = [x for x in rel.split(sep) if x and x != '.'] + if not parts: + raise ValueError(f"Unacceptable pattern: {str(pattern)!r}") + elif rel.endswith(sep): + # GH-65238: preserve trailing slash in glob patterns. + parts.append('') + return parts + @property def _raw_path(self): """The joined but unnormalized path.""" @@ -641,17 +666,7 @@ def glob(self, pattern, *, case_sensitive=None, recurse_symlinks=False): kind, including directories) matching the given relative pattern. """ sys.audit("pathlib.Path.glob", self, pattern) - if not isinstance(pattern, PurePath): - pattern = self.with_segments(pattern) - if pattern.anchor: - raise NotImplementedError("Non-relative patterns are unsupported") - parts = pattern._tail.copy() - if not parts: - raise ValueError("Unacceptable pattern: {!r}".format(pattern)) - raw = pattern._raw_path - if raw[-1] in (self.parser.sep, self.parser.altsep): - # GH-65238: pathlib doesn't preserve trailing slash. Add it back. - parts.append('') + parts = self._parse_pattern(pattern) select = self._glob_selector(parts[::-1], case_sensitive, recurse_symlinks) root = str(self) paths = select(root) @@ -672,9 +687,7 @@ def rglob(self, pattern, *, case_sensitive=None, recurse_symlinks=False): this subtree. """ sys.audit("pathlib.Path.rglob", self, pattern) - if not isinstance(pattern, PurePath): - pattern = self.with_segments(pattern) - pattern = '**' / pattern + pattern = self.parser.join('**', pattern) return self.glob(pattern, case_sensitive=case_sensitive, recurse_symlinks=recurse_symlinks) def walk(self, top_down=True, on_error=None, follow_symlinks=False): diff --git a/Misc/NEWS.d/next/Library/2024-11-03-14-43-51.gh-issue-126363.Xus7vU.rst b/Misc/NEWS.d/next/Library/2024-11-03-14-43-51.gh-issue-126363.Xus7vU.rst new file mode 100644 index 00000000000000..20fea9b9ef99a0 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2024-11-03-14-43-51.gh-issue-126363.Xus7vU.rst @@ -0,0 +1,2 @@ +Speed up pattern parsing in :meth:`pathlib.Path.glob` by skipping creation +of a :class:`pathlib.Path` object for the pattern. _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3/lists/python-checkins.python.org/ Member address: [email protected]
