The italian children group "Girotondo" from Cambridge, organised - as happened for several years now - the 'Festa di Carnevale', which is typical in Italy for this time of the year.
Children get dressed with some character clothes (typically princesses in my house) and they have a party like that.
They dress what they fancy to be or become....
(Thinking about that, I never dressed as a computer programmer when I was a child!).