Unicode and string conversions

[Salim Zayat]

Hey there.  I was wondering something.  I understand that if you type in 
something like:

uni = u'\u0621\u0622'

uni becomes a unicode string, with two characters and all.  That's cool.  
What I dont understand is how to start with a normal string, something 
like :

str = '\u0621\u0622' or some other way of packaging that info

and convert it to a unicode string that will yield the same result as uni 
above.  Is this even possible?  I have this feeling I am missing some 
glaringly obvious detail.  Any help, including any links to handling 
unicode strings as a whole, would be appreciated.

Salim