from spb import *
import numpy as np
fx = lambda u, v: (4 + np.cos(u)) * np.cos(v)
fy = lambda u, v: (4 + np.cos(u)) * np.sin(v)
fz = lambda u, v: np.sin(u)
graphics(
    surface_parametric(fx, fy, fz, ("u", 0, 2 * np.pi),
        ("v", 0, 2 * np.pi)),
    zlim=(-2.5, 2.5), title="Torus", backend=KB, grid=False)