Text processing and file creation

[malibuster at gmail.com]

I have a text source file of about 20.000 lines.
>From this file, I like to write the first 5 lines to a new file. Close
that file, grab the next 5 lines write these to a new file... grabbing
5 lines and creating new files until processing of all 20.000 lines is
done.
Is there an efficient way to do this in Python?
In advance, thanks for your help.