import matplotlib.pyplot as plt
import matplotlib

def main():
    fig, ax = plt.subplots()
    ax.set(title='Matplotlib {}'.format(matplotlib.__version__))
    annotate(ax, 'Round')
    annotate(ax, 'Square')
    plt.show()

def annotate(ax, text):
    bbox = dict(fc='none')
    x, y = 0.1, 0.1

    if text == 'Round':
        bbox['boxstyle'] = 'round'
        y = 0.5

    ax.annotate(text, xy=(x, y), xytext=(50, 50), size=20,
                xycoords='data', textcoords='offset points',
                bbox=bbox,  arrowprops=dict(arrowstyle='->'))

main()