The first thing we want to say is that Granada is a very safe city for students. Having said that, and taking into account that we won´t teach you self-defense at the program, we will provide you with the best tool: common sense strategies so that you have as few incidents as possible.
The only object allowed in Spain for self-defense is the Defense Sprays. They are already legal in Spain as long as they meet certain requirements. They must be pepper sprays for self-defence, approved, and with 6% capseicine. You can only buy them in gun shops, no internet.
In this link to the Spanish Guardia Civil website you can see all the information in detail.
Keep in mind, that this link gives you information about Spain. If you are going to travel outside of Spain, for example to another European country or Morocco, you are responsible for getting information about it.