Programmer Allen transmigrated into the Harry Potter world but developed a strange illness that randomly changed his form every day; to find a cure he went to Hogwarts to study and became classmates with Harry Potter; he initially only wanted to protect himself and stay far away from trouble, but trouble kept coming to him anyway; he never expected that in this magical world he would apply programming thoughts and even start writing code... PS1: No system; PS2: Deconstructing HP magic using programming thoughts.