Great library first of all. I am not sure if it is wrong from my side, but some of the modules on py-modindex cannot be found or accessed below. Some modules are found, for example for Spain, but then partially they are not listed either.
python3 -c "
import stdnum.gb
print('stdnum.gb:')
for attr in dir(stdnum.gb):
if not attr.startswith('_'):
print(f' - {attr}')
"
result:
stdnum.gb: