building a dict

Jon Clements joncle at
Sat Mar 13 16:58:02 CET 2010

On 13 Mar, 15:28, Patrick Maupin <pmau... at> wrote:
> On Mar 13, 9:05 am, vsoler < at> wrote:
> > Say that "m" is a tuple of 2-tuples
> > m=(('as',3), ('ab',5), (None, 1), ('as',None), ('as',6))
> > and I need to build a "d" dict where each key has an associated list
> > whose first element is the count, and the second is the sum. If a 2-
> > tuple contains a None value, it should be discarded.
> > The expected result is:
> > d={'as':[2, 9], 'ab': [1,5]}
> > How should I proceed? So far I have been unsuccessful. I have tried
> > with a "for" loop.
> Post your first try at a for loop, and people might be willing to
> point out problems, but this is such a basic for loop that it is
> unlikely that anybody is going to write your ENTIRE homework for you.
> Regards,
> Pat

I was thinking it's possibly homework, but looking at previous posts
it's fairly unlikely.

(If it is, then mea culpa, but as Steve has replied, I think I'll
manage to sleep tonight not worrying about the influx of uneducated,
incompetent and otherwise useless developers to the market).

However, they're receiving some 'elegant' solutions which no professor
(unless they're a star pupil - in which case they wouldn't be asking)
would take as having been done by their selves.
(Or at least I hope not)

But yes, I would certainly be interested in the 'unsuccessful
(To the OP, do post your attempts, it does give more validity).



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