form processing question

[WmGill]

I am experimenting with Python, and want to convert some of my PHP scripts
to python cgi scripts.  In PHP I use  PHP_SELF for the action target.  This
way I can "reuse" data in fields (i.e. if the user enters data in a field
then submits the form,  it comes back already filled in on each subsequent
iteration).  I know I can do this in Python, but before I spend a lot of
time, is it very complicated, or can form field values be (re-)populated
easily?

Thanks

Bill