Misuse of list comprehensions?

[Simon Forman]

On May 20, 8:58 am, Paul McGuire <pt... at austin.rr.com> wrote:
> On May 20, 10:50 am, s0s... at gmail.com wrote:
>
>
>
> > You don't need all those conditionals. A set differs from a list
> > precisely in the fact that each element is unique. And since the
> > function is expecting "s" to be an iterable object, it can be
> > constructed even without a for loop:
>
> > def compress(s):
> >     return list(set(s))
>
> > That does the trick.
>
> Only if order does not need to be maintained.  list(set(s)) will not
> necessarily keep the unique characters in the order they are seen.
> We'll have to check with the OP to see if this is important (I just
> assumed that it was because of the use of list comps).
>
> -- Paul


If order is important, you can use sorted() instead of list() like so:

def compress(s):
    new = sorted(set(s), key=s.index)
    return return ''.join(new)

~Simon