GH-73435: Implement recursive wildcards in pathlib.PurePath.match()

Doc/library/pathlib.rst

@@ -569,6 +569,13 @@ Pure paths provide the following methods and properties:
  >>> PurePath('a/b.py').match('/*.py')
  False
 
+ The *pattern* may be another path object; this speeds up matching the same
+ pattern against multiple files::
+
+ >>> pattern = PurePath('*.py')
+ >>> PurePath('a/b.py').match(pattern)
+ True
+
  As with other methods, case-sensitivity follows platform defaults::
 
  >>> PurePosixPath('b.py').match('*.PY')
@@ -581,6 +588,10 @@ Pure paths provide the following methods and properties:
  .. versionadded:: 3.12
  The *case_sensitive* argument.
 
+ .. versionchanged:: 3.13
+ Support for the recursive wildcard "``**``" was added. In previous
+ versions, it acted like the non-recursive wildcard "``*``".
+
 
 .. method:: PurePath.relative_to(other, walk_up=False)
 

Doc/whatsnew/3.13.rst

@@ -90,6 +90,9 @@ Improved Modules
 pathlib
 -------
 
+* Add support for recursive wildcards in :meth:`pathlib.PurePath.match`.
+ (Contributed by Barney Gale in :gh:`73435`.)
+
 * Add *follow_symlinks* keyword-only argument to :meth:`pathlib.Path.glob` and
  :meth:`~pathlib.Path.rglob`.
  (Contributed by Barney Gale in :gh:`77609`.)

Lib/pathlib.py

@@ -54,13 +54,30 @@ def _ignore_error(exception):
  getattr(exception, 'winerror', None) in _IGNORED_WINERRORS)
 
 
+@functools.cache
 def _is_case_sensitive(flavour):
  return flavour.normcase('Aa') == 'Aa'
 
 #
 # Globbing helpers
 #
 
+
+# fnmatch.translate() returns a regular expression that includes a prefix and
+# a suffix, which enable matching newlines and ensure the end of the string is
+# matched, respectively. These features are undesirable for our implementation
+# of PurePatch.match(), which represents path separators as newlines and joins
+# pattern segments together. As a workaround, we define a slice object that
+# can remove the prefix and suffix from any translate() result. See the
+# _compile_pattern_lines() function for more details.
+_FNMATCH_PREFIX, _FNMATCH_SUFFIX = fnmatch.translate('_').split('_')
+_FNMATCH_SLICE = slice(len(_FNMATCH_PREFIX), -len(_FNMATCH_SUFFIX))
+_SWAP_SEP_AND_NEWLINE = {
+ '/': str.maketrans({'/': '\n', '\n': '/'}),
+ '\\': str.maketrans({'\\': '\n', '\n': '\\'}),
+}
+
+
 @functools.lru_cache()
 def _make_selector(pattern_parts, flavour, case_sensitive):
  pat = pattern_parts[0]
@@ -92,6 +109,51 @@ def _compile_pattern(pat, case_sensitive):
  return re.compile(fnmatch.translate(pat), flags).match
 
 
+@functools.lru_cache()
+def _compile_pattern_lines(pattern_lines, case_sensitive):
+ """Compile the given pattern lines to an `re.Pattern` object.
+
+ The *pattern_lines* argument is a glob-style pattern (e.g. '**/*.py') with
+ its path separators and newlines swapped (e.g. '**\n*.py`). By using
+ newlines to separate path components, and not setting `re.DOTALL`, we
+ ensure that the `*` wildcard cannot match path separators.
+
+ The returned `re.Pattern` object may have its `match()` method called to
+ match a complete pattern, or `search()` to match from the right. The
+ argument supplied to these methods must also have its path separators and
+ newlines swapped.
+ """
+
+ # Match the start of the path, or just after a path separator
+ parts = ['^']
+ for part in pattern_lines.splitlines(keepends=True):
+ if part == '**\n':
+ # '**/' component: we use '[\s\S]' rather than '.' so that path
+ # separators (i.e. newlines) are matched. The trailing '^' ensures
+ # we terminate after a path separator (i.e. on a new line).
+ part = r'[\s\S]*^'
+ elif part == '**':
+ # '**' component.
+ part = r'[\s\S]*'
+ elif '**' in part:
+ raise ValueError("Invalid pattern: '**' can only be an entire path component")
+ else:
+ # Any other component: pass to fnmatch.translate(). We slice off
+ # the common prefix and suffix added by translate() to ensure that
+ # re.DOTALL is not set, and the end of the string not matched,
+ # respectively. With DOTALL not set, '*' wildcards will not match
+ # path separators, because the '.' characters in the pattern will
+ # not match newlines.
+ part = fnmatch.translate(part)[_FNMATCH_SLICE]
+ parts.append(part)
+ # Match the end of the path, always.
+ parts.append(r'\Z')
+ flags = re.MULTILINE
+ if not case_sensitive:
+ flags |= re.IGNORECASE
+ return re.compile(''.join(parts), flags=flags)
+
+
 class _Selector:
  """A selector matches a specific glob pattern part against the children
  of a given path."""
@@ -276,6 +338,10 @@ class PurePath:
  # to implement comparison methods like `__lt__()`.
  '_parts_normcase_cached',
 
+ # The `_lines_cached` slot stores the string path with path separators
+ # and newlines swapped. This is used to implement `match()`.
+ '_lines_cached',
+
  # The `_hash` slot stores the hash of the case-normalized string
  # path. It's set when `__hash__()` is called for the first time.
  '_hash',
@@ -441,6 +507,16 @@ def _parts_normcase(self):
  self._parts_normcase_cached = self._str_normcase.split(self._flavour.sep)
  return self._parts_normcase_cached
 
+ @property
+ def _lines(self):
+ # Path with separators and newlines swapped, for pattern matching.
+ try:
+ return self._lines_cached
+ except AttributeError:
+ trans = _SWAP_SEP_AND_NEWLINE[self._flavour.sep]
+ self._lines_cached = str(self).translate(trans)
+ return self._lines_cached
+
  def __eq__(self, other):
  if not isinstance(other, PurePath):
  return NotImplemented
@@ -697,23 +773,18 @@ def match(self, path_pattern, *, case_sensitive=None):
  """
  Return True if this path matches the given pattern.
  """
+ if not isinstance(path_pattern, PurePath):
+ path_pattern = self.with_segments(path_pattern)
  if case_sensitive is None:
  case_sensitive = _is_case_sensitive(self._flavour)
- pat = self.with_segments(path_pattern)
- if not pat.parts:
+ pattern = _compile_pattern_lines(path_pattern._lines, case_sensitive)
+ if path_pattern.drive or path_pattern.root:
+ return pattern.match(self._lines) is not None
+ elif path_pattern._tail:
+ return pattern.search(self._lines) is not None
+ else:
  raise ValueError("empty pattern")
- pat_parts = pat.parts
- parts = self.parts
- if pat.drive or pat.root:
- if len(pat_parts) != len(parts):
- return False
- elif len(pat_parts) > len(parts):
- return False
- for part, pat in zip(reversed(parts), reversed(pat_parts)):
- match = _compile_pattern(pat, case_sensitive)
- if not match(part):
- return False
- return True
+
 
 # Subclassing os.PathLike makes isinstance() checks slower,
 # which in turn makes Path construction slower. Register instead!

Lib/test/test_pathlib.py

@@ -310,8 +310,30 @@ def test_match_common(self):
  self.assertFalse(P('/ab.py').match('/a/*.py'))
  self.assertFalse(P('/a/b/c.py').match('/a/*.py'))
  # Multi-part glob-style pattern.
- self.assertFalse(P('/a/b/c.py').match('/**/*.py'))
+ self.assertTrue(P('a').match('**'))
+ self.assertTrue(P('c.py').match('**'))
+ self.assertTrue(P('a/b/c.py').match('**'))
+ self.assertTrue(P('/a/b/c.py').match('**'))
+ self.assertTrue(P('/a/b/c.py').match('/**'))
+ self.assertTrue(P('/a/b/c.py').match('**/'))
+ self.assertTrue(P('/a/b/c.py').match('/a/**'))
+ self.assertTrue(P('/a/b/c.py').match('**/*.py'))
+ self.assertTrue(P('/a/b/c.py').match('/**/*.py'))
  self.assertTrue(P('/a/b/c.py').match('/a/**/*.py'))
+ self.assertTrue(P('/a/b/c.py').match('/a/b/**/*.py'))
+ self.assertTrue(P('/a/b/c.py').match('/**/**/**/**/*.py'))
+ self.assertFalse(P('c.py').match('**/a.py'))
+ self.assertFalse(P('c.py').match('c/**'))
+ self.assertFalse(P('a/b/c.py').match('**/a'))
+ self.assertFalse(P('a/b/c.py').match('**/a/b'))
+ self.assertFalse(P('a/b/c.py').match('**/a/b/c'))
+ self.assertFalse(P('a/b/c.py').match('**/a/b/c.'))
+ self.assertFalse(P('a/b/c.py').match('**/a/b/c./**'))
+ self.assertFalse(P('a/b/c.py').match('**/a/b/c./**'))
+ self.assertFalse(P('a/b/c.py').match('/a/b/c.py/**'))
+ self.assertFalse(P('a/b/c.py').match('/**/a/b/c.py'))
+ self.assertRaises(ValueError, P('a').match, '**a/b/c')
+ self.assertRaises(ValueError, P('a').match, 'a/b/c**')
  # Case-sensitive flag
  self.assertFalse(P('A.py').match('a.PY', case_sensitive=True))
  self.assertTrue(P('A.py').match('a.PY', case_sensitive=False))

Misc/NEWS.d/next/Library/2023-02-17-18-56-46.gh-issue-73435.7sTJHk.rst

@@ -0,0 +1 @@
+Add support for recursive wildcards in :meth:`pathlib.PurePath.match`.