write text in matplotlib code example

Example 1: plt text matplotlib white background

import numpy as np
import matplotlib.pyplot as plt
plt.figure()
ax = plt.subplot(111)
plt.plot(np.linspace(1,0,1000))
t = plt.text(0.03,.95,'text',transform=ax.transAxes,backgroundcolor='0.75',alpha=.5)
plt.show()

Example 2: add caption to plot python

txt="I need the caption to be present a little below X-axis"
plt.figtext(0.5, 0.01, txt, wrap=True, horizontalalignment='center', fontsize=12)