How come tuples don't have an index method?

[Terry Reedy]

"Michael Abbott" <michael at rcp.co.uk> wrote in message
news:Xns91157F87ABEE6michaelrcpcouk at 194.238.50.13...
> Some code:
>
>     months = ['JAN', 'FEB', 'MAR', 'APR', 'MAY', 'JUN',
>               'JUL', 'AUG', 'SEP', 'OCT', 'NOV', 'DEC']
>
>     ...
>
>         # Raises an exception iff the value doesn't start with a
month
>         monthIn = months.index(value[:3]) + 1
>
> I thought, just for tidiness, and to ensure that the months array
doesn't
> accidentially get modified in place, that I'd change it into a
tuple.
>
> Unfortunately, I can't call months.index anymore!
>
> Is there a good reason for not supporting index on tuples?  And for
that
> matter, why not also support count?

Historically, immutable types did not have attributes.  But then
complex numbers with z.real, z.imag came along, then strings got
methods, so I see no good reason not to give tuples methods also.
Seems like a PEP project.

Terry J. Reedy