Filtering a Python list to uniques

[Jerry Hill]

On Wed, Mar 26, 2008 at 2:50 PM, kellygreer1 <kellygreer1 at yahoo.com> wrote:
>  How come the Set() thing seems to work for some people and I get the
>  'unhashable' error?
>
>  How do you test for 'membership' on a dictionary?
>
>  # where tmp is the non-unique list
>  # dct is a dictionary where each unique key will be tied to a count
>  (the value)
>  # for testing I was setting the count to 0
>  for v in tmp:
>     if not v in dct: dct[v] = 0
>
>  # I get unhashable error here.
>  # Even if I write it.
>
>  for v in tmp:
>     if not v in dct.keys(): dct[v] = 0
>
>  What am I missing?

Some of the elements of tmp are unhashable. Unhashable items can't be
the keys of a dictionary or members of a set.  I don't think you've
said anywhere in the thread what these items are, you just started out
with an example of a list of integers.  Do you believe the elements in
tmp are integers?  If so, try the following -

for v in tmp:
    print type(v), repr(v), hash(v)

and let us know what it spits out.

-- 
Jerry