unicode encoding problem

[garykpdx at hotmail.com]

Every time I think I understand unicode, I prove I don't.

I created a variable in interactive mode like this:
s = u'ä'
where this character is the a-umlaut
that worked alright. Then I encoded it like this:
s.encode( 'latin1')

and it printed out a sigma (totally wrong)

then I typed this:
s.encode( 'utf-8')

Then it gave me two weird characters +ñ

So how do I tell what encoding my unicode string is in, and how do I
retrieve that when I read it from a file?