My original article about this topic is more that year old and was using Regional Internet Registries (RIRs) list as source and was in python. This post will describe other simple solution how to generate some country IP ranges list.
There are many sites providing country blocklists, for example http://www.ip2location.com/free/visitor-blocker or https://www.countryipblocks.net/. When you want periodicaly update such list, you have problem. You need pay for that service for automated access, actual data or “hack” access to that service (abuse their free access conditions)…