import matplotlib.pyplot as plt
from matplotlib.patches import Circle, PathPatch
from mpl_toolkits.mplot3d import Axes3D
import mpl_toolkits.mplot3d.art3d as art3d
fig = plt.figure()
ax = fig.gca(projection='3d')
for i in ['x', 'y', 'z']:
    circle = Circle((0, 0), 1)
ax.add_patch(circle)
art3d.pathpatch_2d_to_3d(circle, z=0, zdir=i)
ax.set_xlim3d(-2, 2)
ax.set_ylim3d(-2, 2)
ax.set_zlim3d(-2, 2)
plt.show()
How to plot a 3D patch collection in matplotlib?