Thomas Wouters pointed out that _Abstract.__new__ should use super().__new__()
instead of going straight to object.__new__().
diff --git a/Lib/abc.py b/Lib/abc.py
index ad5a523..f8e0230 100644
--- a/Lib/abc.py
+++ b/Lib/abc.py
@@ -56,8 +56,6 @@
"""Helper class inserted into the bases by ABCMeta (using _fix_bases()).
You should never need to explicitly subclass this class.
-
- There should never be a base class between _Abstract and object.
"""
def __new__(cls, *args, **kwds):
@@ -69,7 +67,7 @@
if (args or kwds) and cls.__init__ is object.__init__:
raise TypeError("Can't pass arguments to __new__ "
"without overriding __init__")
- return object.__new__(cls)
+ return super().__new__(cls)
@classmethod
def __subclasshook__(cls, subclass):
diff --git a/Lib/test/test_abc.py b/Lib/test/test_abc.py
index f93f3d3..008d839 100644
--- a/Lib/test/test_abc.py
+++ b/Lib/test/test_abc.py
@@ -130,6 +130,20 @@
self.failUnless(issubclass(MyInt, A))
self.failUnless(isinstance(42, A))
+ def test_all_new_methods_are_called(self):
+ class A(metaclass=abc.ABCMeta):
+ pass
+ class B:
+ counter = 0
+ def __new__(cls):
+ B.counter += 1
+ return super().__new__(cls)
+ class C(A, B):
+ pass
+ self.assertEqual(B.counter, 0)
+ C()
+ self.assertEqual(B.counter, 1)
+
def test_main():
test_support.run_unittest(TestABC)