mylist = [-1,0,1,2,3,4];
a = [i*2 for i in mylist];print(a) #[-2, 0, 2, 4, 6, 8]
a = [i*2 for i in mylist if i>0];print(a); #[2, 4, 6, 8]
a = [i*2 for i in mylist if i not in [-1,0,1]];print(a); #[4, 6, 8]