diff --git a/Lib/dataclasses.py b/Lib/dataclasses.py index 3c72c289e43..21f3fa5c213 100644 --- a/Lib/dataclasses.py +++ b/Lib/dataclasses.py @@ -575,15 +575,15 @@ def _init_fn(fields, std_fields, kw_only_fields, frozen, has_post_init, # message, and future-proofs us in case we build up the function # using ast. - seen_default = False + seen_default = None for f in std_fields: # Only consider the non-kw-only fields in the __init__ call. if f.init: if not (f.default is MISSING and f.default_factory is MISSING): - seen_default = True + seen_default = f elif seen_default: raise TypeError(f'non-default argument {f.name!r} ' - 'follows default argument') + f'follows default argument {seen_default.name!r}') locals = {f'__dataclass_type_{f.name}__': f.type for f in fields} locals.update({ diff --git a/Lib/test/test_dataclasses.py b/Lib/test/test_dataclasses.py index 6669f1c57e2..bd8d8243841 100644 --- a/Lib/test/test_dataclasses.py +++ b/Lib/test/test_dataclasses.py @@ -134,7 +134,7 @@ class TestCase(unittest.TestCase): # Non-defaults following defaults. with self.assertRaisesRegex(TypeError, "non-default argument 'y' follows " - "default argument"): + "default argument 'x'"): @dataclass class C: x: int = 0 @@ -143,7 +143,7 @@ class TestCase(unittest.TestCase): # A derived class adds a non-default field after a default one. with self.assertRaisesRegex(TypeError, "non-default argument 'y' follows " - "default argument"): + "default argument 'x'"): @dataclass class B: x: int = 0 @@ -156,7 +156,7 @@ class TestCase(unittest.TestCase): # a field which didn't use to have a default. with self.assertRaisesRegex(TypeError, "non-default argument 'y' follows " - "default argument"): + "default argument 'x'"): @dataclass class B: x: int @@ -4521,7 +4521,7 @@ class TestKeywordArgs(unittest.TestCase): # Make sure we still check for non-kwarg non-defaults not following # defaults. - err_regex = "non-default argument 'z' follows default argument" + err_regex = "non-default argument 'z' follows default argument 'a'" with self.assertRaisesRegex(TypeError, err_regex): @dataclass class A: