remove a list from a list

[John Henry]

from sets import Set as set   # Python 2.3

b = list( set([i.upper() for i in b) - set([i.upper() for i in a] ) )


Rares Vernica wrote:
> Yeah, I ended up doing a similar kind of loop. That is pretty messy.
>
> Is there any other way?
>
> Thanks,
> Ray
>
> Tim Chase wrote:
> >> That is a nice solution.
> >>
> >> But, how about modifying the list in place?
> >>
> >> That is, l would become ['c', 'D'].
> >>
> >>>  >>> e = ['a', 'b', 'e']
> >>>  >>> l = ['A', 'a', 'c', 'D', 'E']
> >>>  >>> s = set(e)
> >>>  >>> [x for x in l if x.lower() not in s]
> >>> ['c', 'D']
> >
> >
> > Well...changing the requirements midstream, eh? ;-)
> >
> > You can just change that last item to be a reassignment if "l" is
> > all you care about:
> >
> >  >>> l = [x for x in l ...]
> >
> > Things get a bit hairier if you *must* do it in-place.  You'd
> > have to do something like this (untested)
> >
> > for i in xrange(len(l), 0, -1):
> > 	if l[i-1].lower() in s:
> > 		del l[i-1]
> > 
> > 
> > which should do the job.
> > 
> > -tkc
> > 
> > 
> >