import random

import numpy as np
import matplotlib as mpl
import matplotlib.pyplot as plt
import matplotlib.dates as mdates

from mpl_toolkits.mplot3d import Axes3D

mpl.rcParams['font.size'] = 10

fig = plt.figure()
ax = fig.add_subplot(111, projection='3d')

for z in [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]:
     xs = range(1,32)
     ys = 1000 * np.random.rand(31)

     color =plt.cm.Set2(random.choice(range(plt.cm.Set2.N)))
     ax.bar(xs, ys, zs=z, zdir='y', color=color, alpha=0.8)

ax.xaxis.set_major_locator(mpl.ticker.FixedLocator(xs))
ax.yaxis.set_major_locator(mpl.ticker.FixedLocator(ys))

ax.set_xlabel('Month')
ax.set_ylabel('Year')
ax.set_zlabel('Sales Net [usd]')

plt.show()