From efb13be72cbf49edf591936fafb120fe1b7d59f7 Mon Sep 17 00:00:00 2001 From: Ethan Furman Date: Thu, 10 Dec 2020 12:20:06 -0800 Subject: bpo-42385: [Enum] add `_generate_next_value_` to StrEnum (GH-23735) The default for auto() is to return an integer, which doesn't work for `StrEnum`. The new `_generate_next_value_` for `StrEnum` returns the member name, lower cased. --- Doc/library/enum.rst | 6 ++++-- Lib/enum.py | 6 ++++++ Lib/test/test_enum.py | 6 ++++++ Misc/NEWS.d/next/Library/2020-12-09-19-45-32.bpo-42385.boGbjo.rst | 1 + 4 files changed, 17 insertions(+), 2 deletions(-) create mode 100644 Misc/NEWS.d/next/Library/2020-12-09-19-45-32.bpo-42385.boGbjo.rst diff --git a/Doc/library/enum.rst b/Doc/library/enum.rst index a9584b9..a0b078c 100644 --- a/Doc/library/enum.rst +++ b/Doc/library/enum.rst @@ -67,10 +67,12 @@ helper, :class:`auto`. .. class:: auto - Instances are replaced with an appropriate value for Enum members. By default, the initial value starts at 1. + Instances are replaced with an appropriate value for Enum members. + :class:`StrEnum` defaults to the lower-cased version of the member name, + while other Enums default to 1 and increase from there. .. versionadded:: 3.6 ``Flag``, ``IntFlag``, ``auto`` - +.. versionadded:: 3.10 ``StrEnum`` Creating an Enum ---------------- diff --git a/Lib/enum.py b/Lib/enum.py index 74318c3..ed0c9ce 100644 --- a/Lib/enum.py +++ b/Lib/enum.py @@ -826,6 +826,12 @@ class StrEnum(str, Enum): __str__ = str.__str__ + def _generate_next_value_(name, start, count, last_values): + """ + Return the lower-cased version of the member name. + """ + return name.lower() + def _reduce_ex_by_name(self, proto): return self.name diff --git a/Lib/test/test_enum.py b/Lib/test/test_enum.py index 7ca54e9..f245eb6 100644 --- a/Lib/test/test_enum.py +++ b/Lib/test/test_enum.py @@ -2179,6 +2179,12 @@ class TestEnum(unittest.TestCase): self.assertEqual(Private._Private__corporal, 'Radar') self.assertEqual(Private._Private__major_, 'Hoolihan') + def test_strenum_auto(self): + class Strings(StrEnum): + ONE = auto() + TWO = auto() + self.assertEqual([Strings.ONE, Strings.TWO], ['one', 'two']) + class TestOrder(unittest.TestCase): diff --git a/Misc/NEWS.d/next/Library/2020-12-09-19-45-32.bpo-42385.boGbjo.rst b/Misc/NEWS.d/next/Library/2020-12-09-19-45-32.bpo-42385.boGbjo.rst new file mode 100644 index 0000000..f95da85 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2020-12-09-19-45-32.bpo-42385.boGbjo.rst @@ -0,0 +1 @@ +StrEnum: fix _generate_next_value_ to return a str -- cgit v0.12