pythonGH-101357: Suppress OSError from pathlib.Path.exists() and is_*()

Suppress all `OSError` exceptions from `pathlib.Path.exists()` and `is_*()`
rather than a selection of more common errors as we do presently. Also
adjust the implementations to call `os.path.exists()` etc, which are much
faster on Windows thanks to pythonGH-101196.

Author: barneygale

Doc/library/pathlib.rst

@@ -874,7 +874,7 @@ Methods
 ^^^^^^^
 
 Concrete paths provide the following methods in addition to pure paths
-methods.  Many of these methods can raise an :exc:`OSError` if a system
+methods.  Some of these methods can raise an :exc:`OSError` if a system
 call fails (for example because the path doesn't exist).
 
 .. versionchanged:: 3.8
@@ -886,6 +886,12 @@ call fails (for example because the path doesn't exist).
    instead of raising an exception for paths that contain characters
    unrepresentable at the OS level.
 
+.. versionchanged:: 3.14
+
+   The methods given above now return ``False`` instead of raising an
+   :exc:`OSError` exception from the operating system. In previous versions,
+   some kinds of :exc:`OSError` exception are raised, and others suppressed.
+
 
 .. classmethod:: Path.cwd()
 
@@ -1071,8 +1077,8 @@ call fails (for example because the path doesn't exist).
    Return ``True`` if the path points to a directory, ``False`` if it points
    to another kind of file.
 
-   ``False`` is also returned if the path doesn't exist or is a broken symlink;
-   other errors (such as permission errors) are propagated.
+   ``False`` is also returned if the path doesn't exist, or is a broken
+   symlink, or is inaccessible for any other reason.
 
    This method normally follows symlinks; to exclude symlinks to directories,
    add the argument ``follow_symlinks=False``.
@@ -1086,8 +1092,8 @@ call fails (for example because the path doesn't exist).
    Return ``True`` if the path points to a regular file, ``False`` if it
    points to another kind of file.
 
-   ``False`` is also returned if the path doesn't exist or is a broken symlink;
-   other errors (such as permission errors) are propagated.
+   ``False`` is also returned if the path doesn't exist, or is a broken
+   symlink, or is inaccessible for any other reason.
 
    This method normally follows symlinks; to exclude symlinks, add the
    argument ``follow_symlinks=False``.
@@ -1125,8 +1131,8 @@ call fails (for example because the path doesn't exist).
 
    Return ``True`` if the path points to a symbolic link, ``False`` otherwise.
 
-   ``False`` is also returned if the path doesn't exist; other errors (such
-   as permission errors) are propagated.
+   ``False`` is also returned if the path doesn't exist or is inaccessible for
+   any other reason.
 
 
 .. method:: Path.is_socket()
@@ -1143,26 +1149,26 @@ call fails (for example because the path doesn't exist).
    Return ``True`` if the path points to a FIFO (or a symbolic link
    pointing to a FIFO), ``False`` if it points to another kind of file.
 
-   ``False`` is also returned if the path doesn't exist or is a broken symlink;
-   other errors (such as permission errors) are propagated.
+   ``False`` is also returned if the path doesn't exist, or is a broken
+   symlink, or is inaccessible for any other reason.
 
 
 .. method:: Path.is_block_device()
 
    Return ``True`` if the path points to a block device (or a symbolic link
    pointing to a block device), ``False`` if it points to another kind of file.
 
-   ``False`` is also returned if the path doesn't exist or is a broken symlink;
-   other errors (such as permission errors) are propagated.
+   ``False`` is also returned if the path doesn't exist, or is a broken
+   symlink, or is inaccessible for any other reason.
 
 
 .. method:: Path.is_char_device()
 
    Return ``True`` if the path points to a character device (or a symbolic link
    pointing to a character device), ``False`` if it points to another kind of file.
 
-   ``False`` is also returned if the path doesn't exist or is a broken symlink;
-   other errors (such as permission errors) are propagated.
+   ``False`` is also returned if the path doesn't exist, or is a broken
+   symlink, or is inaccessible for any other reason.
 
 
 .. method:: Path.iterdir()

Lib/glob.py

@@ -339,7 +339,7 @@ def __init__(self, sep, case_sensitive, case_pedantic=False, recursive=False):
 
     # Low-level methods
 
-    lstat = staticmethod(os.lstat)
+    lexists = staticmethod(os.path.lexists)
     scandir = staticmethod(os.scandir)
     parse_entry = operator.attrgetter('path')
     concat_path = operator.add
@@ -512,12 +512,8 @@ def select_exists(self, path, exists=False):
             # Optimization: this path is already known to exist, e.g. because
             # it was returned from os.scandir(), so we skip calling lstat().
             yield path
-        else:
-            try:
-                self.lstat(path)
-                yield path
-            except OSError:
-                pass
+        elif self.lexists(path):
+            yield path
 
     @classmethod
     def walk(cls, root, top_down, on_error, follow_symlinks):

Lib/pathlib/__init__.py

@@ -525,12 +525,46 @@ def stat(self, *, follow_symlinks=True):
         """
         return os.stat(self, follow_symlinks=follow_symlinks)
 
+    def exists(self, *, follow_symlinks=True):
+        """
+        Whether this path exists.
+
+        This method normally follows symlinks; to check whether a symlink exists,
+        add the argument follow_symlinks=False.
+        """
+        if follow_symlinks:
+            return os.path.exists(self)
+        return os.path.lexists(self)
+
+    def is_dir(self, *, follow_symlinks=True):
+        """
+        Whether this path is a directory.
+        """
+        if follow_symlinks:
+            return os.path.isdir(self)
+        return _abc.PathBase.is_dir(self, follow_symlinks=follow_symlinks)
+
+    def is_file(self, *, follow_symlinks=True):
+        """
+        Whether this path is a regular file (also True for symlinks pointing
+        to regular files).
+        """
+        if follow_symlinks:
+            return os.path.isfile(self)
+        return _abc.PathBase.is_file(self, follow_symlinks=follow_symlinks)
+
     def is_mount(self):
         """
         Check if this path is a mount point
         """
         return os.path.ismount(self)
 
+    def is_symlink(self):
+        """
+        Whether this path is a symbolic link.
+        """
+        return os.path.islink(self)
+
     def is_junction(self):
         """
         Whether this path is a junction.

Lib/pathlib/_abc.py

@@ -14,37 +14,17 @@
 import functools
 import glob
 import operator
-from errno import ENOENT, ENOTDIR, EBADF, ELOOP, EINVAL
+from errno import ENOTDIR, ELOOP
 from stat import S_ISDIR, S_ISLNK, S_ISREG, S_ISSOCK, S_ISBLK, S_ISCHR, S_ISFIFO
 
-#
-# Internals
-#
-
-_WINERROR_NOT_READY = 21  # drive exists but is not accessible
-_WINERROR_INVALID_NAME = 123  # fix for bpo-35306
-_WINERROR_CANT_RESOLVE_FILENAME = 1921  # broken symlink pointing to itself
-
-# EBADF - guard against macOS `stat` throwing EBADF
-_IGNORED_ERRNOS = (ENOENT, ENOTDIR, EBADF, ELOOP)
-
-_IGNORED_WINERRORS = (
-    _WINERROR_NOT_READY,
-    _WINERROR_INVALID_NAME,
-    _WINERROR_CANT_RESOLVE_FILENAME)
-
-def _ignore_error(exception):
-    return (getattr(exception, 'errno', None) in _IGNORED_ERRNOS or
-            getattr(exception, 'winerror', None) in _IGNORED_WINERRORS)
-
 
 @functools.cache
 def _is_case_sensitive(parser):
     return parser.normcase('Aa') == 'Aa'
 
 
 class Globber(glob._Globber):
-    lstat = operator.methodcaller('lstat')
+    lexists = operator.methodcaller('exists', follow_symlinks=False)
     add_slash = operator.methodcaller('joinpath', '')
 
     @staticmethod
@@ -472,12 +452,7 @@ def exists(self, *, follow_symlinks=True):
         """
         try:
             self.stat(follow_symlinks=follow_symlinks)
-        except OSError as e:
-            if not _ignore_error(e):
-                raise
-            return False
-        except ValueError:
-            # Non-encodable path
+        except (OSError, ValueError):
             return False
         return True
 
@@ -487,14 +462,7 @@ def is_dir(self, *, follow_symlinks=True):
         """
         try:
             return S_ISDIR(self.stat(follow_symlinks=follow_symlinks).st_mode)
-        except OSError as e:
-            if not _ignore_error(e):
-                raise
-            # Path doesn't exist or is a broken symlink
-            # (see http://web.archive.org/web/20200623061726/https://bitbucket.org/pitrou/pathlib/issues/12/ )
-            return False
-        except ValueError:
-            # Non-encodable path
+        except (OSError, ValueError):
             return False
 
     def is_file(self, *, follow_symlinks=True):
@@ -504,14 +472,7 @@ def is_file(self, *, follow_symlinks=True):
         """
         try:
             return S_ISREG(self.stat(follow_symlinks=follow_symlinks).st_mode)
-        except OSError as e:
-            if not _ignore_error(e):
-                raise
-            # Path doesn't exist or is a broken symlink
-            # (see http://web.archive.org/web/20200623061726/https://bitbucket.org/pitrou/pathlib/issues/12/ )
-            return False
-        except ValueError:
-            # Non-encodable path
+        except (OSError, ValueError):
             return False
 
     def is_mount(self):
@@ -540,13 +501,7 @@ def is_symlink(self):
         """
         try:
             return S_ISLNK(self.lstat().st_mode)
-        except OSError as e:
-            if not _ignore_error(e):
-                raise
-            # Path doesn't exist
-            return False
-        except ValueError:
-            # Non-encodable path
+        except (OSError, ValueError):
             return False
 
     def is_junction(self):
@@ -564,14 +519,7 @@ def is_block_device(self):
         """
         try:
             return S_ISBLK(self.stat().st_mode)
-        except OSError as e:
-            if not _ignore_error(e):
-                raise
-            # Path doesn't exist or is a broken symlink
-            # (see http://web.archive.org/web/20200623061726/https://bitbucket.org/pitrou/pathlib/issues/12/ )
-            return False
-        except ValueError:
-            # Non-encodable path
+        except (OSError, ValueError):
             return False
 
     def is_char_device(self):
@@ -580,14 +528,7 @@ def is_char_device(self):
         """
         try:
             return S_ISCHR(self.stat().st_mode)
-        except OSError as e:
-            if not _ignore_error(e):
-                raise
-            # Path doesn't exist or is a broken symlink
-            # (see http://web.archive.org/web/20200623061726/https://bitbucket.org/pitrou/pathlib/issues/12/ )
-            return False
-        except ValueError:
-            # Non-encodable path
+        except (OSError, ValueError):
             return False
 
     def is_fifo(self):
@@ -596,14 +537,7 @@ def is_fifo(self):
         """
         try:
             return S_ISFIFO(self.stat().st_mode)
-        except OSError as e:
-            if not _ignore_error(e):
-                raise
-            # Path doesn't exist or is a broken symlink
-            # (see http://web.archive.org/web/20200623061726/https://bitbucket.org/pitrou/pathlib/issues/12/ )
-            return False
-        except ValueError:
-            # Non-encodable path
+        except (OSError, ValueError):
             return False
 
     def is_socket(self):
@@ -612,14 +546,7 @@ def is_socket(self):
         """
         try:
             return S_ISSOCK(self.stat().st_mode)
-        except OSError as e:
-            if not _ignore_error(e):
-                raise
-            # Path doesn't exist or is a broken symlink
-            # (see http://web.archive.org/web/20200623061726/https://bitbucket.org/pitrou/pathlib/issues/12/ )
-            return False
-        except ValueError:
-            # Non-encodable path
+        except (OSError, ValueError):
             return False
 
     def samefile(self, other_path):