matplotlib painting 3d map

import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D

= Fig plt.figure () 
    AX = Axes3D (Fig) 
    X = np.arange (-4,. 4, 0.25 )
     Print (X) 
    Y = np.arange (-4,. 4, 0.25 ) 
    X, Y = np.meshgrid (X, Y)
     # np.sqrt (X): calculates the square root of each element array 
    R & lt np.sqrt = (X ** 2 + Y ** 2 )
     # height value 
    Z = np.sin (R & lt) 
    ax.plot_surface ( X, Y, Z, rstride =. 1, cstride =. 1, CMap = ' Rainbow ' )
     # zdir that represents the axis projection 
    ax.contourf (X, Y, Z, zdir = ' Z ' , offset = -2, CMap =' Rainbow ' )
     # set the height of the contour line 
    ax.set_zlim (-2, 2 ) 
    plt.savefig ( ' ./image_dir/3d.png ' ) 
    plt.show ()