Backmerge -r59233:59232
Guido said:
Please roll this back. The error message you added is inappropriate
when the parameter to a legitimate register() call is omitted, e.g.
collections.Sequence.register()
diff --git a/Lib/abc.py b/Lib/abc.py
index 30bb6b0..54dc8e2 100644
--- a/Lib/abc.py
+++ b/Lib/abc.py
@@ -137,11 +137,8 @@
cls._abc_negative_cache_version = ABCMeta._abc_invalidation_counter
return cls
- def register(cls, subclass=None):
+ def register(cls, subclass):
"""Register a virtual subclass of an ABC."""
- if subclass is None:
- raise TypeError("register() cannot be called on an ABCMeta "
- "subclass, use class Example(metaclass=abc.ABCMeta) instead.")
if not isinstance(cls, type):
raise TypeError("Can only register classes")
if issubclass(subclass, cls):
diff --git a/Lib/test/test_abc.py b/Lib/test/test_abc.py
index a04b271..e6c8415 100644
--- a/Lib/test/test_abc.py
+++ b/Lib/test/test_abc.py
@@ -146,13 +146,6 @@
C()
self.assertEqual(B.counter, 1)
- def test_error_on_subclass(self):
- class A(abc.ABCMeta):
- pass
- class B:
- pass
- self.assertRaises(TypeError, A.register, B)
-
def test_main():
test_support.run_unittest(TestABC)