bpo-32424: Deprecate xml.etree.ElementTree.Element.copy() in favor of copy.copy() (pythonGH-12995)

Author: GPHemsley

Lib/test/test_xml_etree.py

@@ -2211,6 +2211,35 @@ def test___init__(self):
         self.assertIsNot(element_foo.attrib, attrib)
         self.assertNotEqual(element_foo.attrib, attrib)
 
+    def test_copy(self):
+        # Only run this test if Element.copy() is defined.
+        if "copy" not in dir(ET.Element):
+            raise unittest.SkipTest("Element.copy() not present")
+
+        element_foo = ET.Element("foo", { "zix": "wyp" })
+        element_foo.append(ET.Element("bar", { "baz": "qix" }))
+
+        with self.assertWarns(DeprecationWarning):
+            element_foo2 = element_foo.copy()
+
+        # elements are not the same
+        self.assertIsNot(element_foo2, element_foo)
+
+        # string attributes are equal
+        self.assertEqual(element_foo2.tag, element_foo.tag)
+        self.assertEqual(element_foo2.text, element_foo.text)
+        self.assertEqual(element_foo2.tail, element_foo.tail)
+
+        # number of children is the same
+        self.assertEqual(len(element_foo2), len(element_foo))
+
+        # children are the same
+        for (child1, child2) in itertools.zip_longest(element_foo, element_foo2):
+            self.assertIs(child1, child2)
+
+        # attrib is a copy
+        self.assertEqual(element_foo2.attrib, element_foo.attrib)
+
     def test___copy__(self):
         element_foo = ET.Element("foo", { "zix": "wyp" })
         element_foo.append(ET.Element("bar", { "baz": "qix" }))

Lib/xml/etree/ElementTree.py

@@ -195,6 +195,13 @@ def copy(self):
         original tree.
 
         """
+        warnings.warn(
+            "elem.copy() is deprecated. Use copy.copy(elem) instead.",
+            DeprecationWarning
+            )
+        return self.__copy__()
+
+    def __copy__(self):
         elem = self.makeelement(self.tag, self.attrib)
         elem.text = self.text
         elem.tail = self.tail

Misc/NEWS.d/next/Library/2019-04-28-10-34-19.bpo-32424.eqNPhM.rst

@@ -0,0 +1,3 @@
+Deprecate xml.etree.ElementTree.Element.copy() in favor of copy.copy().
+
+Patch by Gordon P. Hemsley