Since matplotlib in Fedora 25 seems to be having some font issues when using latex fonts and creating pdf or ps files, a workaround is needed. Luckily, PDF files can also be created using the PGF backend. See http://matplotlib.org/users/pgf.html for details

Basically, include these lines in the python script and saving to pdf will work:

from matplotlib.backends.backend_pgf import FigureCanvasPgf
from matplotlib.backend_bases import register_backend
register_backend('pdf', FigureCanvasPgf)

If you need customization of the fonts, that may have to be done through the pgf settings; the page linked above has some examples.