How to efficently build a nested dictionary

[Emile van Sebille]

Any particular reason not to do:

ky = (dir, year, month, day)
p_ttl = traffic.get(key,0)
traffic[ky] = p_ttl + bytes

--

Emile van Sebille
emile at fenx.com
-------------------


"Carsten Gaebler" <cgaebler at gmx.de> wrote in message
news:3AAA2042.E69A53FC at gmx.de...
> Hi there!
>
> I wrote a script for FTP traffic accounting, i.e. for each
"top level"
> FTP directory it counts the bytes transferred per day. The
traffic is
> stored in a dictionary that has the following structure:
>
> traffic = {dir: {year: {month: {day: 42}}}}
>
> for several dirs, years, months, days, of course.
>
> While parsing the FTP log files I am building up the
dictionary in this
> way:
>
> if not traffic.has_key(dir):
>     traffic[dir] = {year: {month: {day: bytes}}}
> elif not traffic[dir].has_key(year):
>     traffic[dir][year] = {month: {day: bytes}}
> elif not traffic[dir][year].has_key(month):
>     traffic[dir][year][month] = {day: bytes}
> elif not traffic[dir][year][month].has_key(day):
>     traffic[dir][year][month][day] = bytes
> else:
>     traffic[dir][year][month][day] += bytes
>
>
> Now, this looks a bit clumsy to me, especially if I
consider
> you-know-which-language-I-mean which would simply allow to
write
> $traffic{$year}{$month}{$day} += $bytes;
>
> Any ideas how to do this more elegantly?
>
> Regards
> Carsten.