To point out specific features in a plot, we can draw arrows with the function plt.arrow(). This code illustrates the different available styles of arrow annotations:

import matplotlib.pyplot as plt

plt.axis([0, 9, 0, 18])
arrstyles = ['-', '->', '-[', '<-', '<->', 'fancy', 'simple', 'wedge']
for i, style in enumerate(arrstyles):
 plt.annotate(style, xytext=(1, 2+2*i), xy=(4, 1+2*i), 
 arrowprops=dict(arrowstyle=style))
connstyles=["arc", "arc,angleA=10,armA=30,rad=15", 
 "arc3,rad=.2", "arc3,rad=-.2", "angle", "angle3"]

for i, style in enumerate(connstyles):
 plt.annotate("", xytext=(6, 2+2*i), xy=(8, 1+2*i), 
 arrowprops=dict(arrowstyle='->', connectionstyle=style))

plt.show()

It generates the following figure to list the available arrow shapes for annotation: