Anyone know where to learn about basslines like these

hey im getting into the dutch house like hardwell dont have a problem writing the melodys just having a bit of trouble with bassline melodies anyone know of any tutorials or can help me out tried to find some midis of basslines just to have a look at but had no luck so any help would be appreciated

helps if i put a link Avicii - Levels (Clockwork Remix) - YouTube

Hardwell - Cobra (Official Teaser) OUT NOW! - YouTube