Convert hole patterns from DXF file to G-Code

I recently needed to generate some odd hole patterns for drilling sheet metal and have written a small python program to read a dxf file and convert it to g-code for my sherline mill.
The holes must be circles and be on the holes layer (case is not important e.g., Holes or HOLES be OK).
Attached are the program plus a sample dxf along with the resultant ngc file.
I only use this for single hole sizes but if there are differing hole sizes it will split the code into sections of hole sizes but there is no tool change code (you could insert this manually in the output text box then save the file again).
Cheers, Phill

I used Tkinter...
wiki.python.org/moin/TkInter

Just a quick tip. If you want a circle of holes, it is quite easy to MDI them using polar coordinates.

You need to touch off so the centre of the pattern is X=0 Y=0.
The G81 drilling canned-cycle takes a repeat parameter (L)

So,Will drill a circle of 6 holes at a radius of 2 units and a depth of 0.126 units.

Thanks, I do use polar coordinates in one of my NGCGUI routines.