insert unique data in a list

[Gary Herron]

mattia wrote:
> How can I insert non-duplicate data in a list? I mean, is there a 
> particular option in the creation of a list that permit me not to use 
> something like:
> def append_unique(l, val):
>     if val not in l:
>         l.append(val)
>
> Thanks, 
> Mattia
>   

Unless the insertion order is important, you could use a set -- where a 
second insertion will have no effect.

 >>> s = set()
 >>> s.add(1)
 >>> s.add(2)
 >>> s.add(1)
 >>> print s
set([1, 2])


Gary Herron