ordered sets operations on lists..

[Raymond Hettinger]

[Amit Khemka]
> > Hello, Is there a *direct* way of doing set operations on lists which
> > preserve the order of the input lists ?
> > For Ex.  l1 = [1, 5, 3, 2, 4, 7]
> >             l2 =  [3, 5,  10]
> >
> > and (l1 intersect l2)  returns [5, 3]     .... (and (l2 intersect l1)

[bonono]
> what do you mean by "direct" way ? ugly(some said) one liner ?
>
> filter(set(l1).intersection(set(l2)).__contains__, l1)
> filter(set(l1).intersection(set(l2)).__contains__, l2)

The intersection step is unnecessary, so the answer can be simplified a
bit:

>>> filter(set(l2).__contains__, l1)
[5, 3]
>>> filter(set(l1).__contains__, l2)
[3, 5]