On 9/19/20 11:32 AM, Guido van Rossum wrote:
> On Sat, Sep 19, 2020 at 1:29 AM Ethan Furman wrote:
>> On 9/18/20 6:41 PM, Guido van Rossum wrote:
>>> Another brainstorm (or brainfart): maybe repr() should show the
>>> module/class and the name, and str() should only show the name. We'd
>>> then get
>>> ```
>>> >>> # Mock-up!
>>> >>> print(str(re.i))
>>> IGNORE
>>> >>> print(repr(re.i))
>>> re.IGNORE
>>> >>>
>>> ```
>>> and similar for Color.RED:
>>> ```
>>> >>> # Another mock-up!
>>> >>> print(str(Color.RED))
>>> RED
>>> >>> print(repr(Color.RED))
>>> Color.RED
>>> >>>
>>> ```
>>
>> I think that's too terse -- the first bit, whether class or module,
>> repr or str, is very important -- especially if you have several
>> enums using some of the same names for their members.
>
> Hm, the more I think about it the more I like this proposal. :-)
>
> When exploring in the REPL, my proposal *would* show the class name
> (but not the module name -- one can cause obfuscation that way too,
> but it would become unwieldy, and the custom seems to be to stop
> short of that).
>
> But when printing casually, wouldn't it be nice if we could cause
> end-user-friendly output to be produced by default? End users probably
> don't care about the class name, but they would care about the color
> name. E.g.
>
> class Color(Enum):
> red = 0
> green = 1
> blue = 2
>
> class Flowers(Enum):
> roses = 0
> violets = 1
>
> def send_bouquet(flowers, color):
> print("I'm sending you a bouquet of", color, flowers)
That's a fun example -- but member names are supposed to be UPPER_CASE,
so your string would be, for example:
I'm sending you a bouquet of RED VIOLETS
Of course, if we went with the idea of __str__ just returning the value,
then:
class Color(Enum):
RED = 'red'
GREEN = 'green'
BLUE = 'blue'
class Flowers(Enum):
ROSES = 'roses'
VIOLETS = violets'
which would indeed give us:
I'm sending you a bouquet of red violets
and the above enums could be even simpler if using enum.auto() and a
custom NamedEnum:
class NamedEnum(Enum):
"""
member values are the lower-cased member names
"""
def _generate_next_value_(name, start, count, last_values):
return name.lower()
class Flowers(NamedEnum):
ROSES = auto()
VIOLETS = auto()
--
~Ethan~
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