First run setup.py in Blender (see below)
setup.py only needs to be run the first time you start Blender. After that, the exec command can be repeatedly called to generate new cities.
exec(compile(open(filename_test).read(), filename_test, 'exec'))
filename_test = "C:/projects/citytastic/main.py"
exec(compile(open(filename_test).read(), filename_test, 'exec'))```