Revert "bpo-38811: Check for presence of os.link method in pathlib. (G…

…H-17170)"

This reverts commit 111772f.

Lib/pathlib.py

@@ -418,12 +418,7 @@ def lchmod(self, pathobj, mode):
 
     unlink = os.unlink
 
-    if hasattr(os, "link"):
-        link_to = os.link
-    else:
-        @staticmethod
-        def link_to(self, target):
-            raise NotImplementedError("os.link() not available on this system")
+    link_to = os.link
 
     rmdir = os.rmdir
 
@@ -435,7 +430,6 @@ def link_to(self, target):
         if supports_symlinks:
             symlink = os.symlink
         else:
-            @staticmethod
             def symlink(a, b, target_is_directory):
                 raise NotImplementedError("symlink() not available on this system")
     else:

Lib/test/test_pathlib.py

@@ -1759,7 +1759,6 @@ def test_rmdir(self):
         self.assertFileNotFound(p.stat)
         self.assertFileNotFound(p.unlink)
 
-    @unittest.skipUnless(hasattr(os, "link"), "os.link() is not present")
     def test_link_to(self):
         P = self.cls(BASE)
         p = P / 'fileA'
@@ -1779,15 +1778,6 @@ def test_link_to(self):
         self.assertEqual(os.stat(r).st_size, size)
         self.assertTrue(q.stat)
 
-    @unittest.skipIf(hasattr(os, "link"), "os.link() is present")
-    def test_link_to_not_implemented(self):
-        P = self.cls(BASE)
-        p = P / 'fileA'
-        # linking to another path.
-        q = P / 'dirA' / 'fileAA'
-        with self.assertRaises(NotImplementedError):
-            p.link_to(q)
-
     def test_rename(self):
         P = self.cls(BASE)
         p = P / 'fileA'
@@ -2021,15 +2011,6 @@ def test_symlink_to(self):
         self.assertTrue(link.is_dir())
         self.assertTrue(list(link.iterdir()))
 
-    @unittest.skipIf(support.can_symlink(), "symlink support is present")
-    def test_symlink_to_not_implemented(self):
-        P = self.cls(BASE)
-        target = P / 'fileA'
-        # Symlinking a path target.
-        link = P / 'dirA' / 'linkAA'
-        with self.assertRaises(NotImplementedError):
-            link.symlink_to(target)
-
     def test_is_dir(self):
         P = self.cls(BASE)
         self.assertTrue((P / 'dirA').is_dir())