Summing a 2D list

[Karsten Heymann]

Hi Björn,

"BJörn Lindqvist" <bjourne at gmail.com> writes:
> On Fri, Jun 13, 2008 at 2:12 PM, Karsten Heymann
> <karsten.heymann at blue-cable.net> wrote:
>> summed_up={}
>> for user,vote in pairs:
>>  if summed_up.has_key(user):
>>    summed_up[user]+=vote
>>  else:
>>    summed_up[user]=vote
>
> You'll save even more by using:
>
> if user in summed_up:
>
> instead of has_key.

You're right, then it goes down to 1.5s (compared to 0.9 for the pure
list version). Pythons dictionaries are really great :-)

Yours
Karsten