So the idea is to start with a double A (i.e. AA) through, in this case, GR.
Here is the error:
Runtime error
Traceback (most recent call last):
File "<string>", line 54, in <module>
File "<string>", line 22, in main
RuntimeError: cannot open 'C:\JVRP\Legio_Grid.shp'
I get the same error after switching off line 40.
I think part of the problem, at least, is the feature class location... The data source says the database is in a location separate from the shapefile.
edit: Yeah, that was creating the error. Now the issue is that the first square in the grid is A0, as opposed to AA1.