Plotting multiple 3d Plots using subplots

I tried to plot 2 3d plots using subplotting and it gave me error . the code is as follow :

import numpy as np
from mpl_toolkits.mplot3d import Axes3D
import matplotlib.pyplot as pp
fig = pp.figure()
pp.subplot(121)
axes = fig.gca(projection = '3d')
print(axes)  #Used to get x and y cordinates of current figure in subplot
axes.plot_surface(a,b,a**0+5)
pp.show()
pp.subplot(122)
axes2 = fig.gca(projection ='3d')
axes2.plot_surface(a,b,a*2+b*2)
pp.show() 

Also please explain what axes is and what GCD is used here for … From my research it has been used to tell the figure container that figure will be 3d and GCD returns co-ordinates of where it will be plotted .

Thank you
Dinesh

please specify the error that was shown and in which line it was shown.

Ok sir , i will post the error here soon . And please sir can u provide more explanation about axes and gcd function too along with it?

look at the documentation at matplotlib site for explation about gca function and axes.
they are not concepts just functions so there explanation is only the role they play in plotting graph which is given in documentation.