/usr/lib/pymodules/python2.7/matplotlib/legend.py:610: UserWarning: Legend does not support <mpl_toolkits.mplot3d.art3d.Patch3DCollection object at 0x3bf46d0>
Use proxy artist instead."

import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D
import random
import csv
from os import listdir
from os.path import isfile, join

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

handles = []
colors = ['blue', 'red']

X1 = range(0,10)
Y1 = range(0,10)
Z1 = range(0,10)

random.shuffle(X1)
random.shuffle(Y1)
random.shuffle(Z1)

scatter1 = ax.scatter(X1, Y1, Z1, c = colors[0], marker = 'o')

random.shuffle(X1)
random.shuffle(Y1)
random.shuffle(Z1)

scatter2 = ax.scatter(X1, Y1, Z1, c = colors[1], marker = 'v')

ax.set_xlabel('X', fontsize = 10)
ax.set_ylabel('Y', fontsize = 10)
ax.set_zlabel('Z', fontsize = 10)

ax.legend([scatter1, scatter2], ['label1', 'label2'])

plt.show()

scatter1_proxy = matplotlib.lines.Line2D([0],[0], linestyle="none", c=colors[0], marker = 'o')
scatter2_proxy = matplotlib.lines.Line2D([0],[0], linestyle="none", c=colors[1], marker = 'v')
ax.legend([scatter1_proxy, scatter2_proxy], ['label1', 'label2'], numpoints = 1)