LP#1981760: Register "Element.attrib" as collections.abc.MutableMapping.

2 files changed, 16 insertions, 1 deletions

diff --git a/src/lxml/etree.pyx b/src/lxml/etree.pyx
index 95dd21ee..c0d236bd 100644
--- a/src/lxml/etree.pyx
+++ b/src/lxml/etree.pyx
@@ -87,6 +87,7 @@ from itertools import islice
 
 cdef object ITER_EMPTY = iter(())
 
+cdef object MutableMapping
 try:
     from collections.abc import MutableMapping  # Py3.3+
 except ImportError:
@@ -113,7 +114,7 @@ class _ImmutableMapping(MutableMapping):
     iterkeys = itervalues = iteritems = __iter__
 
 cdef object IMMUTABLE_EMPTY_MAPPING = _ImmutableMapping()
-del MutableMapping, _ImmutableMapping
+del _ImmutableMapping
 
 
 # the rules
@@ -2568,6 +2569,8 @@ cdef class _Attrib:
             return NotImplemented
         return python.PyObject_RichCompare(one, other, op)
 
+MutableMapping.register(_Attrib)
+
 
 @cython.final
 @cython.internal
diff --git a/src/lxml/tests/test_etree.py b/src/lxml/tests/test_etree.py
index 3e52258e..8bf82c08 100644
--- a/src/lxml/tests/test_etree.py
+++ b/src/lxml/tests/test_etree.py
@@ -241,6 +241,18 @@ class ETreeOnlyTestCase(HelperTestCase):
         a[0].clear(keep_tail=True)
         self.assertEqual(_bytes('<a aa="A"><b/>B2<c ca="C">C1</c>C2</a>'), tostring(a))
 
+    def test_attrib_is_Mapping(self):
+        try:
+            from collections.abc import Mapping, MutableMapping
+        except ImportError:
+            from collections import Mapping, MutableMapping  # Py2
+
+        Element = self.etree.Element
+        root = Element("root")
+
+        self.assertTrue(isinstance(root.attrib, Mapping))
+        self.assertTrue(isinstance(root.attrib, MutableMapping))
+
     def test_attribute_has_key(self):
         # ET in Py 3.x has no "attrib.has_key()" method
         XML = self.etree.XML