[Python-ideas] Enum and random.choice

[Nick Coghlan]

On 21 Oct 2013 15:52, "Antony Lee" <antony.lee at berkeley.edu> wrote:
>
> random.choice and Enum interact poorly, because indexing an enum class
doesn't work as choice expects:
>
> >>> import enum, random
> >>> class C(enum.Enum): a, b = 1, 2
> ...
> >>> random.choice(C)
> <traceback...>
> KeyError: 1
>
> Of course one can do `random.choice(list(C.__members__.values()))` but
this feels a bit awkward.
>
> The source for random.choice is
>
> def choice(self, seq):
>     """Choose a random element from a non-empty sequence."""
>     try:
>         i = self._randbelow(len(seq))
>     except ValueError:
>         raise IndexError('Cannot choose from an empty sequence')
>     return seq[i]
>
> Adding seq = list(seq) should be enough to fix this.

How is this different from passing a dict to random.choice? Enum classes
are iterables, not sequences.

Cheers,
Nick.

>
> Antony
>
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