dict initialization

[mattia]

Il Tue, 22 Dec 2009 23:09:04 +0100, Peter Otten ha scritto:

> mattia wrote:
> 
>> Is there a function to initialize a dictionary? Right now I'm using:
>> d = {x+1:[] for x in range(50)}
>> Is there any better solution?
> 
> There is a dictionary variant that you don't have to initialize:
> 
> from collections import defaultdict
> d = defaultdict(list)
> 
> Peter

Great, thanks. Now when I call the dict key I also initialize the value, 
good also using something like:
if d[n]:
    d[n].append(val)