From a9ba8ba9a71f3cb8d274c354ff67b6206abeb8ac Mon Sep 17 00:00:00 2001 From: Ethan Furman Date: Wed, 16 Sep 2020 17:37:51 -0700 Subject: [3.9] bpo-39728: Enum: fix duplicate `ValueError` (GH-22277) (GH-22282) fix default `_missing_` to return `None` instead of raising a `ValueError` Co-authored-by: Andrey Darascheka (cherry picked from commit c95ad7a91fbd7636f33a098d3b39964ab083bf49) Co-authored-by: Ethan Furman --- Lib/enum.py | 2 +- Lib/test/test_enum.py | 19 ++++++++++++++++++- Misc/ACKS | 1 + .../Library/2020-02-24-10-58-34.bpo-39728.kOOaHn.rst | 1 + 4 files changed, 21 insertions(+), 2 deletions(-) create mode 100644 Misc/NEWS.d/next/Library/2020-02-24-10-58-34.bpo-39728.kOOaHn.rst diff --git a/Lib/enum.py b/Lib/enum.py index da5a31f..ebadd9f 100644 --- a/Lib/enum.py +++ b/Lib/enum.py @@ -628,7 +628,7 @@ class Enum(metaclass=EnumMeta): @classmethod def _missing_(cls, value): - raise ValueError("%r is not a valid %s" % (value, cls.__qualname__)) + return None def __repr__(self): return "<%s.%s: %r>" % ( diff --git a/Lib/test/test_enum.py b/Lib/test/test_enum.py index 6f54716..0e6b1b1 100644 --- a/Lib/test/test_enum.py +++ b/Lib/test/test_enum.py @@ -1832,6 +1832,18 @@ class TestEnum(unittest.TestCase): third = auto() self.assertEqual([Dupes.first, Dupes.second, Dupes.third], list(Dupes)) + def test_default_missing(self): + class Color(Enum): + RED = 1 + GREEN = 2 + BLUE = 3 + try: + Color(7) + except ValueError as exc: + self.assertTrue(exc.__context__ is None) + else: + raise Exception('Exception not raised.') + def test_missing(self): class Color(Enum): red = 1 @@ -1850,7 +1862,12 @@ class TestEnum(unittest.TestCase): # trigger not found return None self.assertIs(Color('three'), Color.blue) - self.assertRaises(ValueError, Color, 7) + try: + Color(7) + except ValueError as exc: + self.assertTrue(exc.__context__ is None) + else: + raise Exception('Exception not raised.') try: Color('bad return') except TypeError as exc: diff --git a/Misc/ACKS b/Misc/ACKS index 2a180eb..5e0953a 100644 --- a/Misc/ACKS +++ b/Misc/ACKS @@ -432,6 +432,7 @@ Marcos Donolo Dima Dorfman Yves Dorfsman Michael Dorman +Andrey Doroschenko Steve Dower Allen Downey Cesar Douady diff --git a/Misc/NEWS.d/next/Library/2020-02-24-10-58-34.bpo-39728.kOOaHn.rst b/Misc/NEWS.d/next/Library/2020-02-24-10-58-34.bpo-39728.kOOaHn.rst new file mode 100644 index 0000000..beb2016 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2020-02-24-10-58-34.bpo-39728.kOOaHn.rst @@ -0,0 +1 @@ +fix default `_missing_` so a duplicate `ValueError` is not set as the `__context__` of the original `ValueError` -- cgit v0.12