Alright here's the deal, if you are self sponsored meaning willing to pay for the training by yourself 12th grade leaving exam is enough and they will accept you with that. They won't even have as strict physical requirements if you are self sponsored. But if you are talking about Ethiopian Airlines Group sponsored training, you need to have a Bachelor's Degree in any of Science Technology Engineering or Math (STEM) departments from legally known universities. And the physica requirement are also strict (you need to be 1.70 meter if you are male and 1.68 if you are female, need to have normal Body Mass Index, Perfect vision condition glasses may be allowed but not really and keep your hygiene) and there will be entrance exam after that there will be theory classes then simulator training then aircraft training finally you do your solos and within two years the training is over! If you are self sponsored you will need to apply for a job when Ethiopian airline or any airline posts a vacancy like any other job but if you are Ethiopian Sponsored you will start flying directly on the De Havilland Canada DC8 (Local flights) and work your way up the ladder Boeing 737(Regional Flights), Boeing 767 (only cargo currently), Boeing 787/777 (if you are rated on one you can fly the other and they fly internationally) or you can go the airbus way too. I hope this help you understand the rough image. Good Luck!