import rhinoscriptsyntax as rs
import random as ran
rs.DeleteObjects(rs.AllObjects())
z=0
pts=[0]
circle=[0]

while z<15:
    if (z%2==0):
        x=ran.random()
        y=ran.random()
        a=rs.AddPoint(2+x, 3*y, 15*z)
        pts.append(a)
        c1=rs.AddCircle(a,z*3+9)
        circle.append(c1)
    else:
        b=rs.AddPoint(x*2,y,15*z)
        pts.append(b)
        c2=rs.AddCircle(b, z*3+5)
        circle.append(c2)
    z=z+1

rs.AddLoftSrf(circle, loft_type=0)