finding the intersection of a list of Sets

[Suresh Jeevanandam]

I have a list of sets in variable lsets .

Now I want to find the intersection of all the sets.

r = lsets[0]
for s in r[0:]:
r = r & s

Is there any other shorter way?

Thanks in advance,
Suresh

[Peter Otten]

Suresh Jeevanandam wrote:

I have a list of sets in variable lsets .
Now I want to find the intersection of all the sets.

r = lsets[0]
for s in r[0:]:
r = r & s
Try to post working examples.
Is there any other shorter way?

sets = map(set, "abc bcd cde".split())
reduce(set.intersection, sets)

set(['c'])

Peter

[Raymond Hettinger]

[Peter Otten]

sets = map(set, "abc bcd cde".split())
reduce(set.intersection, sets) set(['c'])

Very nice. Here's a refinement:

sets.sort(key=len)
reduce(set.intersection, sets[1:], sets[0])

set(['c'])

[Raymond Hettinger]

That should have been:

sets.sort(key=len)
reduce(set.intersection, sets)

The only refinement was the pre-sort based on set length.