Unique Elements in a List

[Paul Rubin]

"superprad at gmail.com" <superprad at gmail.com> writes:
> Is there an easy way to grab the Unique elements from a list?
> For Example:
> data = [0.1,0.5,0.6,0.4,0.1,0.5,0.6,0.9]

Untested: here's an iterator that gives you the index and value,
without reordering.  Uses dicts instead of sets for backwards compatibility.

def unique_elements(data):
    seen = {}
    for n,x in data:
       if x not in seen:
          seen[x] = 1
          yield n,x