There are a few posts on StackOverflow about changing the font used by matplotlib, but I was not able to find a practical solution, particularly if the font is not part of the current set of system fonts.

To use a new font:

1. (Optional) Install the font in the system;

$ apt-get install msttcorefonts

2. Copy the font to matplotlib font directory. In this case, it’s in a virtualenv (server);

$ cp usr/share/fonts/truetype/msttcorefonts/Times_New_Roman* ~/.virtualenvs/server/lib/python2.7/site-packages/matplotlib/mpl-data/fonts/ttf

3. Clear the font cache;

$ rm ~/.cache/matplotlib/fontList.cache

The font should be available for plotting. Testing with the scatter example from matplotlib’s documentation:

import numpy as np
import matplotlib.pyplot as plt

plt.rc('font',family='Times New Roman')

N = 50
area = np.pi * (15 * np.random.rand(N))**2 
plt.scatter(np.random.rand(N), 
            np.random.rand(N), 
            s=area, 
            c=np.random.rand(N), 
            alpha=0.5)
plt.title("Sample title")
plt.ylabel("Random Value")
plt.xlabel("Random Variable")
plt.show()

Note: If the font is not rendered, it may be because matplotlib needs to refresh its font cache (see Kevin’s comment):

import matplotlib
matplotlib.font_manager._rebuild()