def rot_axis3(theta):
 ct = cos(theta)
 st = sin(theta)
 lil = ((ct, st, 0), ((- st), ct, 0), (0, 0, 1))
 return Matrix(lil)

def rot_axis3 ( theta ) : ct = cos ( theta ) st = sin ( theta ) lil = ( ( ct , st , 0 ) , ( ( - st ) , ct , 0 ) , ( 0 , 0 , 1 ) ) return Matrix ( lil )
returns a rotation matrix for a rotation of theta about the 3-axis .