import numpy as np
import matplotlib.pyplot as plt
from matplotlib.backends.backend_pdf import PdfPages

x = np.random.randn(1000)

fig = plt.figure()
ax = fig.add_subplot(1,1,1)
ax.hist(x, 100)

ax.set_title('Normal distribution with $\mu=0, \sigma=1$')

with PdfPages('foo.pdf') as pdf:
    pdf.savefig(fig)