import matplotlib.pyplot as plt
import matplotlib.patches as mpatches

fig, ax = plt.subplots(1,1)

ax.plot([1,2,3], [4,5,10])
arrow = mpatches.FancyArrowPatch((1.5,2), (3,4), arrowstyle='->', mutation_scale=20,)

ax.add_patch(arrow)

plt.show()