GH-110109: Churn pathlib.PurePath methods (#112012)

Re-arrange `pathlib.PurePath` methods in source code. No other changes.

The `PurePath` implementations of certain special methods, such as
`__eq__()` and `__hash__()`, are not usually applicable to user subclasses
of `_PathBase`. To facilitate their removal, another patch will split the
`PurePath` class into `_PurePathBase` and `PurePath`, with the latter
providing these special methods.

This patch prepares the ground for splitting `PurePath`. It's similar to
e8d77b0, which preceded splitting `Path`. By churning the methods here,
subsequent patches will be easier to review and less likely to break
things.

Lib/pathlib.py

@@ -246,44 +246,6 @@ class PurePath:
     )
     pathmod = os.path
 
-    def __new__(cls, *args, **kwargs):
-        """Construct a PurePath from one or several strings and or existing
-        PurePath objects.  The strings and path objects are combined so as
-        to yield a canonicalized path, which is incorporated into the
-        new PurePath object.
-        """
-        if cls is PurePath:
-            cls = PureWindowsPath if os.name == 'nt' else PurePosixPath
-        return object.__new__(cls)
-
-    def __reduce__(self):
-        # Using the parts tuple helps share interned path parts
-        # when pickling related paths.
-        return (self.__class__, self.parts)
-
-    def __init__(self, *args):
-        paths = []
-        for arg in args:
-            if isinstance(arg, PurePath):
-                if arg.pathmod is ntpath and self.pathmod is posixpath:
-                    # GH-103631: Convert separators for backwards compatibility.
-                    paths.extend(path.replace('\\', '/') for path in arg._raw_paths)
-                else:
-                    paths.extend(arg._raw_paths)
-            else:
-                try:
-                    path = os.fspath(arg)
-                except TypeError:
-                    path = arg
-                if not isinstance(path, str):
-                    raise TypeError(
-                        "argument should be a str or an os.PathLike "
-                        "object where __fspath__ returns a str, "
-                        f"not {type(path).__name__!r}")
-                paths.append(path)
-        self._raw_paths = paths
-        self._resolving = False
-
     def with_segments(self, *pathsegments):
         """Construct a new path object from any number of path-like objects.
         Subclasses may override this method to customize how new path objects
@@ -351,96 +313,14 @@ class PurePath:
                                                   self._tail) or '.'
             return self._str
 
-    def __fspath__(self):
-        return str(self)
-
     def as_posix(self):
         """Return the string representation of the path with forward (/)
         slashes."""
         return str(self).replace(self.pathmod.sep, '/')
 
-    def __bytes__(self):
-        """Return the bytes representation of the path.  This is only
-        recommended to use under Unix."""
-        return os.fsencode(self)
-
     def __repr__(self):
         return "{}({!r})".format(self.__class__.__name__, self.as_posix())
 
-    def as_uri(self):
-        """Return the path as a URI."""
-        if not self.is_absolute():
-            raise ValueError("relative path can't be expressed as a file URI")
-
-        drive = self.drive
-        if len(drive) == 2 and drive[1] == ':':
-            # It's a path on a local drive => 'file:///c:/a/b'
-            prefix = 'file:///' + drive
-            path = self.as_posix()[2:]
-        elif drive:
-            # It's a path on a network drive => 'file://host/share/a/b'
-            prefix = 'file:'
-            path = self.as_posix()
-        else:
-            # It's a posix path => 'file:///etc/hosts'
-            prefix = 'file://'
-            path = str(self)
-        from urllib.parse import quote_from_bytes
-        return prefix + quote_from_bytes(os.fsencode(path))
-
-    @property
-    def _str_normcase(self):
-        # String with normalized case, for hashing and equality checks
-        try:
-            return self._str_normcase_cached
-        except AttributeError:
-            if _is_case_sensitive(self.pathmod):
-                self._str_normcase_cached = str(self)
-            else:
-                self._str_normcase_cached = str(self).lower()
-            return self._str_normcase_cached
-
-    @property
-    def _parts_normcase(self):
-        # Cached parts with normalized case, for comparisons.
-        try:
-            return self._parts_normcase_cached
-        except AttributeError:
-            self._parts_normcase_cached = self._str_normcase.split(self.pathmod.sep)
-            return self._parts_normcase_cached
-
-    def __eq__(self, other):
-        if not isinstance(other, PurePath):
-            return NotImplemented
-        return self._str_normcase == other._str_normcase and self.pathmod is other.pathmod
-
-    def __hash__(self):
-        try:
-            return self._hash
-        except AttributeError:
-            self._hash = hash(self._str_normcase)
-            return self._hash
-
-    def __lt__(self, other):
-        if not isinstance(other, PurePath) or self.pathmod is not other.pathmod:
-            return NotImplemented
-        return self._parts_normcase < other._parts_normcase
-
-    def __le__(self, other):
-        if not isinstance(other, PurePath) or self.pathmod is not other.pathmod:
-            return NotImplemented
-        return self._parts_normcase <= other._parts_normcase
-
-    def __gt__(self, other):
-        if not isinstance(other, PurePath) or self.pathmod is not other.pathmod:
-            return NotImplemented
-        return self._parts_normcase > other._parts_normcase
-
-    def __ge__(self, other):
-        if not isinstance(other, PurePath) or self.pathmod is not other.pathmod:
-            return NotImplemented
-        return self._parts_normcase >= other._parts_normcase
-
     @property
     def drive(self):
         """The drive prefix (letter or UNC path), if any."""
@@ -694,6 +574,126 @@ class PurePath:
         match = _compile_pattern(pattern_str, sep, case_sensitive)
         return match(str(self)) is not None
 
+    def __new__(cls, *args, **kwargs):
+        """Construct a PurePath from one or several strings and or existing
+        PurePath objects.  The strings and path objects are combined so as
+        to yield a canonicalized path, which is incorporated into the
+        new PurePath object.
+        """
+        if cls is PurePath:
+            cls = PureWindowsPath if os.name == 'nt' else PurePosixPath
+        return object.__new__(cls)
+
+    def __init__(self, *args):
+        paths = []
+        for arg in args:
+            if isinstance(arg, PurePath):
+                if arg.pathmod is ntpath and self.pathmod is posixpath:
+                    # GH-103631: Convert separators for backwards compatibility.
+                    paths.extend(path.replace('\\', '/') for path in arg._raw_paths)
+                else:
+                    paths.extend(arg._raw_paths)
+            else:
+                try:
+                    path = os.fspath(arg)
+                except TypeError:
+                    path = arg
+                if not isinstance(path, str):
+                    raise TypeError(
+                        "argument should be a str or an os.PathLike "
+                        "object where __fspath__ returns a str, "
+                        f"not {type(path).__name__!r}")
+                paths.append(path)
+        self._raw_paths = paths
+        self._resolving = False
+
+    def __reduce__(self):
+        # Using the parts tuple helps share interned path parts
+        # when pickling related paths.
+        return (self.__class__, self.parts)
+
+    def __fspath__(self):
+        return str(self)
+
+    def __bytes__(self):
+        """Return the bytes representation of the path.  This is only
+        recommended to use under Unix."""
+        return os.fsencode(self)
+
+    @property
+    def _str_normcase(self):
+        # String with normalized case, for hashing and equality checks
+        try:
+            return self._str_normcase_cached
+        except AttributeError:
+            if _is_case_sensitive(self.pathmod):
+                self._str_normcase_cached = str(self)
+            else:
+                self._str_normcase_cached = str(self).lower()
+            return self._str_normcase_cached
+
+    def __hash__(self):
+        try:
+            return self._hash
+        except AttributeError:
+            self._hash = hash(self._str_normcase)
+            return self._hash
+
+    def __eq__(self, other):
+        if not isinstance(other, PurePath):
+            return NotImplemented
+        return self._str_normcase == other._str_normcase and self.pathmod is other.pathmod
+
+    @property
+    def _parts_normcase(self):
+        # Cached parts with normalized case, for comparisons.
+        try:
+            return self._parts_normcase_cached
+        except AttributeError:
+            self._parts_normcase_cached = self._str_normcase.split(self.pathmod.sep)
+            return self._parts_normcase_cached
+
+    def __lt__(self, other):
+        if not isinstance(other, PurePath) or self.pathmod is not other.pathmod:
+            return NotImplemented
+        return self._parts_normcase < other._parts_normcase
+
+    def __le__(self, other):
+        if not isinstance(other, PurePath) or self.pathmod is not other.pathmod:
+            return NotImplemented
+        return self._parts_normcase <= other._parts_normcase
+
+    def __gt__(self, other):
+        if not isinstance(other, PurePath) or self.pathmod is not other.pathmod:
+            return NotImplemented
+        return self._parts_normcase > other._parts_normcase
+
+    def __ge__(self, other):
+        if not isinstance(other, PurePath) or self.pathmod is not other.pathmod:
+            return NotImplemented
+        return self._parts_normcase >= other._parts_normcase
+
+    def as_uri(self):
+        """Return the path as a URI."""
+        if not self.is_absolute():
+            raise ValueError("relative path can't be expressed as a file URI")
+
+        drive = self.drive
+        if len(drive) == 2 and drive[1] == ':':
+            # It's a path on a local drive => 'file:///c:/a/b'
+            prefix = 'file:///' + drive
+            path = self.as_posix()[2:]
+        elif drive:
+            # It's a path on a network drive => 'file://host/share/a/b'
+            prefix = 'file:'
+            path = self.as_posix()
+        else:
+            # It's a posix path => 'file:///etc/hosts'
+            prefix = 'file://'
+            path = str(self)
+        from urllib.parse import quote_from_bytes
+        return prefix + quote_from_bytes(os.fsencode(path))
+
 
 # Subclassing os.PathLike makes isinstance() checks slower,
 # which in turn makes Path construction slower. Register instead!

Lib/test/test_pathlib.py

@@ -117,33 +117,6 @@ class PurePathTest(unittest.TestCase):
         with self.assertRaises(TypeError):
             p >= q
 
-    def test_bytes(self):
-        P = self.cls
-        message = (r"argument should be a str or an os\.PathLike object "
-                   r"where __fspath__ returns a str, not 'bytes'")
-        with self.assertRaisesRegex(TypeError, message):
-            P(b'a')
-        with self.assertRaisesRegex(TypeError, message):
-            P(b'a', 'b')
-        with self.assertRaisesRegex(TypeError, message):
-            P('a', b'b')
-        with self.assertRaises(TypeError):
-            P('a').joinpath(b'b')
-        with self.assertRaises(TypeError):
-            P('a') / b'b'
-        with self.assertRaises(TypeError):
-            b'a' / P('b')
-        with self.assertRaises(TypeError):
-            P('a').match(b'b')
-        with self.assertRaises(TypeError):
-            P('a').relative_to(b'b')
-        with self.assertRaises(TypeError):
-            P('a').with_name(b'b')
-        with self.assertRaises(TypeError):
-            P('a').with_stem(b'b')
-        with self.assertRaises(TypeError):
-            P('a').with_suffix(b'b')
-
     def _check_str_subclass(self, *args):
         # Issue #21127: it should be possible to construct a PurePath object
         # from a str subclass instance, and it then gets converted to
@@ -273,18 +246,6 @@ class PurePathTest(unittest.TestCase):
             self.assertEqual(P(pathstr).as_posix(), pathstr)
         # Other tests for as_posix() are in test_equivalences().
 
-    def test_as_bytes_common(self):
-        sep = os.fsencode(self.sep)
-        P = self.cls
-        self.assertEqual(bytes(P('a/b')), b'a' + sep + b'b')
-
-    def test_as_uri_common(self):
-        P = self.cls
-        with self.assertRaises(ValueError):
-            P('a').as_uri()
-        with self.assertRaises(ValueError):
-            P().as_uri()
-
     def test_repr_common(self):
         for pathstr in ('a', 'a/b', 'a/b/c', '/', '/a/b', '/a/b/c'):
             with self.subTest(pathstr=pathstr):
@@ -297,17 +258,6 @@ class PurePathTest(unittest.TestCase):
                 inner = r[len(clsname) + 1 : -1]
                 self.assertEqual(eval(inner), p.as_posix())
 
-    def test_repr_roundtrips(self):
-        for pathstr in ('a', 'a/b', 'a/b/c', '/', '/a/b', '/a/b/c'):
-            with self.subTest(pathstr=pathstr):
-                p = self.cls(pathstr)
-                r = repr(p)
-                # The repr() roundtrips.
-                q = eval(r, pathlib.__dict__)
-                self.assertIs(q.__class__, p.__class__)
-                self.assertEqual(q, p)
-                self.assertEqual(repr(q), r)
-
     def test_eq_common(self):
         P = self.cls
         self.assertEqual(P('a/b'), P('a/b'))
@@ -390,34 +340,6 @@ class PurePathTest(unittest.TestCase):
         self.assertTrue(P().match('**'))
         self.assertFalse(P().match('**/*'))
 
-    def test_ordering_common(self):
-        # Ordering is tuple-alike.
-        def assertLess(a, b):
-            self.assertLess(a, b)
-            self.assertGreater(b, a)
-        P = self.cls
-        a = P('a')
-        b = P('a/b')
-        c = P('abc')
-        d = P('b')
-        assertLess(a, b)
-        assertLess(a, c)
-        assertLess(a, d)
-        assertLess(b, c)
-        assertLess(c, d)
-        P = self.cls
-        a = P('/a')
-        b = P('/a/b')
-        c = P('/abc')
-        d = P('/b')
-        assertLess(a, b)
-        assertLess(a, c)
-        assertLess(a, d)
-        assertLess(b, c)
-        assertLess(c, d)
-        with self.assertRaises(TypeError):
-            P() < {}
-
     def test_parts_common(self):
         # `parts` returns a tuple.
         sep = self.sep
@@ -430,12 +352,6 @@ class PurePathTest(unittest.TestCase):
         parts = p.parts
         self.assertEqual(parts, (sep, 'a', 'b'))
 
-    def test_fspath_common(self):
-        P = self.cls
-        p = P('a/b')
-        self._check_str(p.__fspath__(), ('a/b',))
-        self._check_str(os.fspath(p), ('a/b',))
-
     def test_equivalences(self):
         for k, tuples in self.equivalences.items():
             canon = k.replace('/', self.sep)
@@ -787,6 +703,90 @@ class PurePathTest(unittest.TestCase):
             self.assertEqual(hash(pp), hash(p))
             self.assertEqual(str(pp), str(p))
 
+    def test_fspath_common(self):
+        P = self.cls
+        p = P('a/b')
+        self._check_str(p.__fspath__(), ('a/b',))
+        self._check_str(os.fspath(p), ('a/b',))
+
+    def test_bytes(self):
+        P = self.cls
+        message = (r"argument should be a str or an os\.PathLike object "
+                   r"where __fspath__ returns a str, not 'bytes'")
+        with self.assertRaisesRegex(TypeError, message):
+            P(b'a')
+        with self.assertRaisesRegex(TypeError, message):
+            P(b'a', 'b')
+        with self.assertRaisesRegex(TypeError, message):
+            P('a', b'b')
+        with self.assertRaises(TypeError):
+            P('a').joinpath(b'b')
+        with self.assertRaises(TypeError):
+            P('a') / b'b'
+        with self.assertRaises(TypeError):
+            b'a' / P('b')
+        with self.assertRaises(TypeError):
+            P('a').match(b'b')
+        with self.assertRaises(TypeError):
+            P('a').relative_to(b'b')
+        with self.assertRaises(TypeError):
+            P('a').with_name(b'b')
+        with self.assertRaises(TypeError):
+            P('a').with_stem(b'b')
+        with self.assertRaises(TypeError):
+            P('a').with_suffix(b'b')
+
+    def test_as_bytes_common(self):
+        sep = os.fsencode(self.sep)
+        P = self.cls
+        self.assertEqual(bytes(P('a/b')), b'a' + sep + b'b')
+
+    def test_ordering_common(self):
+        # Ordering is tuple-alike.
+        def assertLess(a, b):
+            self.assertLess(a, b)
+            self.assertGreater(b, a)
+        P = self.cls
+        a = P('a')
+        b = P('a/b')
+        c = P('abc')
+        d = P('b')
+        assertLess(a, b)
+        assertLess(a, c)
+        assertLess(a, d)
+        assertLess(b, c)
+        assertLess(c, d)
+        P = self.cls
+        a = P('/a')
+        b = P('/a/b')
+        c = P('/abc')
+        d = P('/b')
+        assertLess(a, b)
+        assertLess(a, c)
+        assertLess(a, d)
+        assertLess(b, c)
+        assertLess(c, d)
+        with self.assertRaises(TypeError):
+            P() < {}
+
+    def test_as_uri_common(self):
+        P = self.cls
+        with self.assertRaises(ValueError):
+            P('a').as_uri()
+        with self.assertRaises(ValueError):
+            P().as_uri()
+
+    def test_repr_roundtrips(self):
+        for pathstr in ('a', 'a/b', 'a/b/c', '/', '/a/b', '/a/b/c'):
+            with self.subTest(pathstr=pathstr):
+                p = self.cls(pathstr)
+                r = repr(p)
+                # The repr() roundtrips.
+                q = eval(r, pathlib.__dict__)
+                self.assertIs(q.__class__, p.__class__)
+                self.assertEqual(q, p)
+                self.assertEqual(repr(q), r)
+
 
 class PurePosixPathTest(PurePathTest):
     cls = pathlib.PurePosixPath