diff --git a/Lib/test/test_csv.py b/Lib/test/test_csv.py index 2411a91110dd..a1e050acd2a0 100644 --- a/Lib/test/test_csv.py +++ b/Lib/test/test_csv.py @@ -1237,6 +1237,9 @@ def test__all__(self): extra = {'__doc__', '__version__'} support.check__all__(self, csv, ('csv', '_csv'), extra=extra) + def test_subclassable(self): + # issue 44089 + class Foo(csv.Error): ... if __name__ == '__main__': unittest.main() diff --git a/Misc/NEWS.d/next/Library/2021-05-09-22-52-34.bpo-44089.IoANsN.rst b/Misc/NEWS.d/next/Library/2021-05-09-22-52-34.bpo-44089.IoANsN.rst new file mode 100644 index 000000000000..b9bd963582fd --- /dev/null +++ b/Misc/NEWS.d/next/Library/2021-05-09-22-52-34.bpo-44089.IoANsN.rst @@ -0,0 +1,2 @@ +Allow subclassing ``csv.Error`` in 3.10 (it was allowed in 3.9 and earlier but +was disallowed in early versions of 3.10). diff --git a/Modules/_csv.c b/Modules/_csv.c index cade1ca9d47f..bdb67fdb4876 100644 --- a/Modules/_csv.c +++ b/Modules/_csv.c @@ -1515,7 +1515,7 @@ static PyType_Slot error_slots[] = { PyType_Spec error_spec = { .name = "_csv.Error", - .flags = Py_TPFLAGS_DEFAULT, + .flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, .slots = error_slots, };