An electron, indeed any particle, is neither a particle nor a wave.
Describing the electron as a particle is a mathematical model
 that works well in some circumstances while describing it as a wave
  is a different mathematical model that works well in other circumstances.
When you choose to do some calculation of the electron's behaviour that treats it
 either as a particle or as a wave, you're not saying the electron is a particle or is a wave:
 
 
 The laws of physics can be viewed as a layer of abstraction between the experimental
  data and the practitioners who want to use specific phenomena to achieve their
  goals, without having to worry about the specifics of the experiments and
  the data that inspired the laws.