#!/usr/bin/env python
# coding: utf-8

# In[4]:


from mpl_toolkits.mplot3d import Axes3D
import matplotlib.pyplot as plt
import numpy as np
from itertools import product, combinations
from matplotlib.patches import FancyArrowPatch
from mpl_toolkits.mplot3d import proj3d

fig = plt.figure()
ax = fig.gca(projection='3d')
ax.set_aspect("auto")

#рисуем сферу
u, v = np.mgrid[0:2*np.pi:20j, 0:np.pi:10j]
x = np.cos(u)*np.sin(v)
y = np.sin(u)*np.sin(v)
z = np.cos(v)
ax.plot_wireframe(x, y, z, color="r")

class Arrow3D(FancyArrowPatch):

    def __init__(self, xs, ys, zs, *args, **kwargs):
        FancyArrowPatch.__init__(self, (0, 0), (0, 0), *args, **kwargs)
        self._verts3d = xs, ys, zs

    def draw(self, renderer):
        xs3d, ys3d, zs3d = self._verts3d
        xs, ys, zs = proj3d.proj_transform(xs3d, ys3d, zs3d, renderer.M)
        self.set_positions((xs[0], ys[0]), (xs[1], ys[1]))
        FancyArrowPatch.draw(self, renderer)

a = Arrow3D([0.5, 1], [-1, 1], [-1, 1], mutation_scale=20,
            lw=1, arrowstyle="-", color="k")
ax.add_artist(a)

plt.show()

