Thank you for your answer.

I have good news and bad news.
The good news is: your method (cn.execute "Update testdb Set testfield = 'Hello'where testfield = 'Sabrina'") I already know. This would work of course.
The bad news is: I did not phrase my question properly. I need the loop to compare the performance in speed between Access and FoxPro tables, and the best way to compare such performance is to use a loop (I suppose).

Can you spend some more time on me?