Anotar Simples01

import matplotlib.pyplot as plt


fig, ax = plt.subplots(figsize=(3, 3))

ax.annotate("",
            xy=(0.2, 0.2), xycoords='data',
            xytext=(0.8, 0.8), textcoords='data',
            arrowprops=dict(arrowstyle="->",
                            connectionstyle="arc3"),
            )

plt.show()