How to efficently build a nested dictionary

[Carsten Gaebler]

Carsten Gaebler wrote:
> 
> Aahz Maruch wrote:
> > >
> > >traffic = {dir: {year: {month: {day: 42}}}}
> >
> > I think Emile's suggestion to use a single compound key is a good one.
> > If that's not sufficient *and* you can use Python 2.0, take a look at
> > the dict.setdefault() method.
> 
> How could the setdefault() method help me out?

By just saying

traffic[dir][year][month][day] =
traffic.setdefault(dir,{}).setdefault(year,{}).setdefault(month,{}).setdefault(day,
0) + bytes

Yes, I know, sometimes I'm a bit slow ... :-)

cg.