[3.10] bpo-43945: [Enum] reduce scope of new format() behavior (GH-26752)
* [Enum] reduce scope of new format behavior
Instead of treating all Enums the same for format(), only user mixed-in
enums will be affected. In other words, IntEnum and IntFlag will not be
changing the format() behavior, due to the requirement that they be
drop-in replacements of existing integer constants.
If a user creates their own integer-based enum, then the new behavior
will apply:
class Grades(int, Enum):
A = 5
B = 4
C = 3
D = 2
F = 0
Now: format(Grades.B) -> DeprecationWarning and '4'
3.12: -> no warning, and 'B'.
(cherry picked from commit f60b07ab6c943fce084772c3c7731ab3bbd213ff)
Co-authored-by: Ethan Furman <ethan@stoneleaf.us>5 files changed