Which Python library - psycopg2 or pygresql?

So I thought, "lets learn a bit of Python", and I stumbled upon
a choice of these two libraries.  Whch would you suggest?
How do they differ?

By the looks of descriptions I am slightly inclined towards
psycopg2, but I would feel better if I talked with people
who actually used these libraries.

   Regards,
     Dawid

PS: I don't want to start a flame war!  I just feel I need a bit
of knowledge-push to get me going. ;-)