"Giovanni Bajo" <[EMAIL PROTECTED]> writes:
> Just today I was writing some code where I wanted to use sets for
> the abstraction (intersection, etc.), but also carry some values
> with them to process. So, yes, I believe that having set-like
> abstraction for dictionaries would be great. In fact,
r = {}
for x in a: if x not in b: r[x] = r[a]
for x in b: if x not in a: r[x] = r[b]
I know, this is wrong :-]
This looks better:
r = {}
for x in a: if x not in b: r[x] = a[x]
for x in b: if x not in a: r[x] = b[x]
Bearophile
--
http://mail.python.org/mailman/listinfo/python-list
Leif K-Brooks:
>They look exactly the same speed-wise to me:
There's a little overhead, you can see it with a bigger test:
.from time import clock
.n = 1*10**6
.
.t1 = clock()
.d = set()
.for i in xrange(n):
. d.add(i)
.t2 = clock()
.for i in xrange(n):
. d.remove(i)
.t3 = clock()
.d = set(xra
On Tue, 01 Feb 2005 00:43:21 +, Raymond Hettinger wrote:
> My guess is that there will be two issues. One is that no one
> implementation of graphs seems to satisfy all users. The second is that
> only a small fraction of Python users need for graph support (there is
> probably a much greater
Raymond Hettinger wrote:
> If set-ifying a dictionary turns out to be an essential and
> time-critical operation, it is possible to add some special case code
> for this. The question is whether it is worth it. If you find the
> need is pressing, file a feature request explaining why it is
> es
You are really gentle Raymond Hettinger, but surely I'm not asking
you/anyone to write some code just for me; I don't have "real
applications", I'm just learning/playing.
Your words are quite good answers to most of my questions.
The only left small topic is about the group/set-like
operations/meth
<[EMAIL PROTECTED]>
> I'm frequently using Py2.4 sets, I find them quite useful, and I like
> them, even if they seem a little slower than dicts.
Glad to hear that you find them to be a useful abstraction.
Since sets are internally implemented as dicts, they should have almost
identical performan
[EMAIL PROTECTED] wrote:
I'm frequently using Py2.4 sets, I find them quite useful, and I like
them, even if they seem a little slower than dicts.
They look exactly the same speed-wise to me:
>>> t1 = Timer('randrange(100) in foo', 'from random import randrange;
foo = set(xrange(1000))')
>>> t2 =
