pythonGH-127381: pathlib ABCs: remove uncommon PurePathBase methods (python#127853)

Remove `PurePathBase.relative_to()` and `is_relative_to()` because they
don't account for *other* being an entirely different kind of path, and
they can't use `__eq__()` because it's not on the `PurePathBase` interface.

Remove `PurePathBase.drive`, `root`, `is_absolute()` and `as_posix()`.
These are all too specific to local filesystems.

Author: barneygale

Lib/pathlib/_abc.py

@@ -205,21 +205,6 @@ def __str__(self):
         passing to system calls."""
         raise NotImplementedError
 
-    def as_posix(self):
-        """Return the string representation of the path with forward (/)
-        slashes."""
-        return str(self).replace(self.parser.sep, '/')
-
-    @property
-    def drive(self):
-        """The drive prefix (letter or UNC path), if any."""
-        return self.parser.splitdrive(self.anchor)[0]
-
-    @property
-    def root(self):
-        """The root of the path, if any."""
-        return self.parser.splitdrive(self.anchor)[1]
-
     @property
     def anchor(self):
         """The concatenation of the drive and root, or ''."""
@@ -291,51 +276,6 @@ def with_suffix(self, suffix):
         else:
             return self.with_name(stem + suffix)
 
-    def relative_to(self, other, *, walk_up=False):
-        """Return the relative path to another path identified by the passed
-        arguments.  If the operation is not possible (because this is not
-        related to the other path), raise ValueError.
-
-        The *walk_up* parameter controls whether `..` may be used to resolve
-        the path.
-        """
-        if not isinstance(other, PurePathBase):
-            other = self.with_segments(other)
-        anchor0, parts0 = _explode_path(self)
-        anchor1, parts1 = _explode_path(other)
-        if anchor0 != anchor1:
-            raise ValueError(f"{str(self)!r} and {str(other)!r} have different anchors")
-        while parts0 and parts1 and parts0[-1] == parts1[-1]:
-            parts0.pop()
-            parts1.pop()
-        for part in parts1:
-            if not part or part == '.':
-                pass
-            elif not walk_up:
-                raise ValueError(f"{str(self)!r} is not in the subpath of {str(other)!r}")
-            elif part == '..':
-                raise ValueError(f"'..' segment in {str(other)!r} cannot be walked")
-            else:
-                parts0.append('..')
-        return self.with_segments(*reversed(parts0))
-
-    def is_relative_to(self, other):
-        """Return True if the path is relative to another path or False.
-        """
-        if not isinstance(other, PurePathBase):
-            other = self.with_segments(other)
-        anchor0, parts0 = _explode_path(self)
-        anchor1, parts1 = _explode_path(other)
-        if anchor0 != anchor1:
-            return False
-        while parts0 and parts1 and parts0[-1] == parts1[-1]:
-            parts0.pop()
-            parts1.pop()
-        for part in parts1:
-            if part and part != '.':
-                return False
-        return True
-
     @property
     def parts(self):
         """An object providing sequence-like access to the
@@ -387,11 +327,6 @@ def parents(self):
             parent = split(path)[0]
         return tuple(parents)
 
-    def is_absolute(self):
-        """True if the path is absolute (has both a root and, if applicable,
-        a drive)."""
-        return self.parser.isabs(str(self))
-
     def match(self, path_pattern, *, case_sensitive=None):
         """
         Return True if this path matches the given pattern. If the pattern is

Lib/pathlib/_local.py

@@ -437,6 +437,11 @@ def _parse_pattern(cls, pattern):
             parts.append('')
         return parts
 
+    def as_posix(self):
+        """Return the string representation of the path with forward (/)
+        slashes."""
+        return str(self).replace(self.parser.sep, '/')
+
     @property
     def _raw_path(self):
         paths = self._raw_paths

Lib/pathlib/_types.py

@@ -15,7 +15,5 @@ class Parser(Protocol):
 
     sep: str
     def split(self, path: str) -> tuple[str, str]: ...
-    def splitdrive(self, path: str) -> tuple[str, str]: ...
     def splitext(self, path: str) -> tuple[str, str]: ...
     def normcase(self, path: str) -> str: ...
-    def isabs(self, path: str) -> bool: ...