def make_legend_arrow(legend, orig_handle, xdescent, ydescent, width,
    height, fontsize):
    p = mpatches.FancyArrow(0, 0.5 * height, width, 0, length_includes_head
        =True, head_width=0.75 * height)
return p
f = plt.figure(figsize=(10, 6))
arrow = plt.arrow(0, 0, 0.5, 0.6, 'dummy', label='My label')
plt.legend([arrow], ['My label'], handler_map={mpatches.FancyArrow:
    HandlerPatch(patch_func=make_legend_arrow)})
Легенда Matplotlib для стрелки