Fixed #1540112: now shutil.copytree will let you provide your own copy() function

Doc/library/shutil.rst

@@ -87,7 +87,7 @@ Directory and files operations
    match one of the glob-style *patterns* provided.  See the example below.
 
 
-.. function:: copytree(src, dst, symlinks=False, ignore=None)
+.. function:: copytree(src, dst, symlinks=False, ignore=None, copy_function=copy2)
 
    Recursively copy an entire directory tree rooted at *src*.  The destination
    directory, named by *dst*, must not already exist; it will be created as well
@@ -111,9 +111,14 @@ Directory and files operations
 
    If exception(s) occur, an :exc:`Error` is raised with a list of reasons.
 
-   The source code for this should be considered an example rather than the
-   ultimate tool.
+   If *copy_function* is given, it must be a callable that will be used
+   to copy each file. It will be called with the source path and the
+   destination path as arguments. By default, :func:`copy2` is used, but any
+   function that supports the same signature (like :func:`copy`) can be used.
 
+   .. versionchanged:: 3.2
+      Added the *copy_function* argument to be able to provide a custom copy
+      function.
 
 .. function:: rmtree(path, ignore_errors=False, onerror=None)
 

Lib/shutil.py

@@ -147,8 +147,8 @@ def ignore_patterns(*patterns):
         return set(ignored_names)
     return _ignore_patterns
 
-def copytree(src, dst, symlinks=False, ignore=None):
-    """Recursively copy a directory tree using copy2().
+def copytree(src, dst, symlinks=False, ignore=None, copy_function=copy2):
+    """Recursively copy a directory tree.
 
     The destination directory must not already exist.
     If exception(s) occur, an Error is raised with a list of reasons.
@@ -170,7 +170,10 @@ def copytree(src, dst, symlinks=False, ignore=None):
     list of names relative to the `src` directory that should
     not be copied.
 
-    XXX Consider this example code rather than the ultimate tool.
+    The optional copy_function argument is a callable that will be used
+    to copy each file. It will be called with the source path and the
+    destination path as arguments. By default, copy2() is used, but any
+    function that supports the same signature (like copy()) can be used.
 
     """
     names = os.listdir(src)
@@ -191,10 +194,10 @@ def copytree(src, dst, symlinks=False, ignore=None):
                 linkto = os.readlink(srcname)
                 os.symlink(linkto, dstname)
             elif os.path.isdir(srcname):
-                copytree(srcname, dstname, symlinks, ignore)
+                copytree(srcname, dstname, symlinks, ignore, copy_function)
             else:
                 # Will raise a SpecialFileError for unsupported file types
-                copy2(srcname, dstname)
+                copy_function(srcname, dstname)
         # catch the Error from the recursive copytree so that we can
         # continue with other files
         except Error as err:

Lib/test/test_shutil.py

@@ -74,6 +74,7 @@ class TestShutil(unittest.TestCase):
         d = tempfile.mkdtemp()
         self.tempdirs.append(d)
         return d
+
     def test_rmtree_errors(self):
         # filename is guaranteed not to exist
         filename = tempfile.mktemp()
@@ -140,11 +141,12 @@ class TestShutil(unittest.TestCase):
         self.assertRaises(OSError, shutil.rmtree, path)
         os.remove(path)
 
+    def _write_data(self, path, data):
+        f = open(path, "w")
+        f.write(data)
+        f.close()
+
     def test_copytree_simple(self):
-        def write_data(path, data):
-            f = open(path, "w")
-            f.write(data)
-            f.close()
 
         def read_data(path):
             f = open(path)
@@ -154,11 +156,9 @@ class TestShutil(unittest.TestCase):
 
         src_dir = tempfile.mkdtemp()
         dst_dir = os.path.join(tempfile.mkdtemp(), 'destination')
-
-        write_data(os.path.join(src_dir, 'test.txt'), '123')
-
+        self._write_data(os.path.join(src_dir, 'test.txt'), '123')
         os.mkdir(os.path.join(src_dir, 'test_dir'))
-        write_data(os.path.join(src_dir, 'test_dir', 'test.txt'), '456')
+        self._write_data(os.path.join(src_dir, 'test_dir', 'test.txt'), '456')
 
         try:
             shutil.copytree(src_dir, dst_dir)
@@ -187,11 +187,6 @@ class TestShutil(unittest.TestCase):
 
     def test_copytree_with_exclude(self):
 
-        def write_data(path, data):
-            f = open(path, "w")
-            f.write(data)
-            f.close()
-
         def read_data(path):
             f = open(path)
             data = f.read()
@@ -204,16 +199,18 @@ class TestShutil(unittest.TestCase):
         src_dir = tempfile.mkdtemp()
         try:
             dst_dir = join(tempfile.mkdtemp(), 'destination')
-            write_data(join(src_dir, 'test.txt'), '123')
-            write_data(join(src_dir, 'test.tmp'), '123')
+            self._write_data(join(src_dir, 'test.txt'), '123')
+            self._write_data(join(src_dir, 'test.tmp'), '123')
             os.mkdir(join(src_dir, 'test_dir'))
-            write_data(join(src_dir, 'test_dir', 'test.txt'), '456')
+            self._write_data(join(src_dir, 'test_dir', 'test.txt'), '456')
             os.mkdir(join(src_dir, 'test_dir2'))
-            write_data(join(src_dir, 'test_dir2', 'test.txt'), '456')
+            self._write_data(join(src_dir, 'test_dir2', 'test.txt'), '456')
             os.mkdir(join(src_dir, 'test_dir2', 'subdir'))
             os.mkdir(join(src_dir, 'test_dir2', 'subdir2'))
-            write_data(join(src_dir, 'test_dir2', 'subdir', 'test.txt'), '456')
-            write_data(join(src_dir, 'test_dir2', 'subdir2', 'test.py'), '456')
+            self._write_data(join(src_dir, 'test_dir2', 'subdir', 'test.txt'),
+                             '456')
+            self._write_data(join(src_dir, 'test_dir2', 'subdir2', 'test.py'),
+                             '456')
 
 
             # testing glob-like patterns
@@ -339,6 +336,21 @@ class TestShutil(unittest.TestCase):
                 shutil.rmtree(TESTFN, ignore_errors=True)
                 shutil.rmtree(TESTFN2, ignore_errors=True)
 
+    def test_copytree_special_func(self):
+
+        src_dir = self.mkdtemp()
+        dst_dir = os.path.join(self.mkdtemp(), 'destination')
+        self._write_data(os.path.join(src_dir, 'test.txt'), '123')
+        os.mkdir(os.path.join(src_dir, 'test_dir'))
+        self._write_data(os.path.join(src_dir, 'test_dir', 'test.txt'), '456')
+
+        copied = []
+        def _copy(src, dst):
+            copied.append((src, dst))
+
+        shutil.copytree(src_dir, dst_dir, copy_function=_copy)
+        self.assertEquals(len(copied), 2)
+
     @unittest.skipUnless(zlib, "requires zlib")
     def test_make_tarball(self):
         # creating something to tar
@@ -728,6 +740,7 @@ class TestMove(unittest.TestCase):
         finally:
             shutil.rmtree(TESTFN, ignore_errors=True)
 
+
 def test_main():
     support.run_unittest(TestShutil, TestMove)
 

Misc/NEWS

@@ -318,6 +318,9 @@ C-API
 Library
 -------
 
+- Issue #1540112: Now allowing the choice of a copy function in 
+  shutil.copytree.
+
 - Issue #4814: timeout parameter is now applied also for connections resulting
   from PORT/EPRT commands.