Using a ttf font file in Matplotlib

Although it is usually not a good idea to explicitly point to a single ttf file for a font instance, you can do so using the font_manager.FontProperties fname argument.

Here, we use the Computer Modern roman font (cmr10) shipped with Matplotlib.

For a more flexible solution, see Configuring the font family and Fonts demo (object-oriented style).

import os
from matplotlib import font_manager as fm, pyplot as plt, rcParams

fig, ax = plt.subplots()

fpath = os.path.join(rcParams["datapath"], "fonts/ttf/cmr10.ttf")
prop = fm.FontProperties(fname=fpath)
fname = os.path.split(fpath)[1]
ax.set_title('This is a special font: {}'.format(fname), fontproperties=prop)
ax.set_xlabel('This is the default font')

plt.show()