storing large amounts of data in a list/dictionary

[flamesrock]

Hi,

Basically, what I'm trying to do is store large amounts of data in a
list or dictionary and then convert that to a custom formatted xml
file.

My list looks roughly like this:
(d[],r[c[d[p[],p[R,C,I]]]])

My question is, would it be faster to use a dictionary if the elements
of the lists have to be put in alphebetical order, or just use lists as
above(since hashes are faster supposedly)?

{d;d[],r;name[{d;d[{p;p[]}],c;name[{d;d[{p;p[]}]}]}]}

Please consider the amount of code necessary to create/decode this

(and sorry if this doesn't make any sense..)

-thanks

 

[Bruno Desthuilliers]

flamesrock a écrit :

Hi,

Basically, what I'm trying to do is store large amounts of data in a
list or dictionary and then convert that to a custom formatted xml
file.

My list looks roughly like this:
(d[],r[c[d[p[],p[R,C,I]]]])

My question is, would it be faster to use a dictionary if the elements
of the lists have to be put in alphebetical order,

....
a
z
e
f

Well... Just *don't* rely on *any* order with dicts.

If you need fast keyed access to a very large dataset, you may want to
have a look at btrees (one possible implementation here :
http://zopewiki.org/BTree).

Now since it's XML related, this may also (or not) be useful:
http://effbot.org/zone/celementtree.htm
http://effbot.org/zone/element-index.htm

HTH
Bruno

 

[flamesrock]

Thanks for the reply

I was hoping not to complicate things with zope, tho Btrees look
interesting.

Oh - and about the xml, I'm using something very similar to elementree
which I found in the python cookbook:
http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/157358

flamesrock a écrit :

Hi,

Basically, what I'm trying to do is store large amounts of data in a
list or dictionary and then convert that to a custom formatted xml
file.

My list looks roughly like this:
(d[],r[c[d[p[],p[R,C,I]]]])

My question is, would it be faster to use a dictionary if the elements
of the lists have to be put in alphebetical order,

d = {"e" : 32, "f": 44, "a" : 1, "z" : 99}
for k in d: print k

...
a
z
e
f

Well... Just *don't* rely on *any* order with dicts.

If you need fast keyed access to a very large dataset, you may want to
have a look at btrees (one possible implementation here :
http://zopewiki.org/BTree).

Now since it's XML related, this may also (or not) be useful:
http://effbot.org/zone/celementtree.htm
http://effbot.org/zone/element-index.htm

HTH
Bruno