Pygal’s country codes are stored in a module called i18n, short for internationalization. The dictionary COUNTRIES contains the two-letter country codes as keys and the country names as values. To see these codes, import the dictionary from the i18n module and print its keys and values:
This is replaced by pygal.maps.world import COUNTRIES
http://pygal.org/en/stable/documentation/types/maps/pygal_maps_world.html
