如何把包含中文字体的matplotlib图件保存为pdf文件

import matplotlib as mpl
from matplotlib.backends.backend_pdf import PdfPages

mpl.rcParams['pdf.fonttype']=42
mpl.rcParams['font.family']='WenQuanYi Zen Hei'

with PdfPages('test.pdf') as pdf:
xxxx # plot some figure
pdf.savefig()

#questions/45870858/runtimeerror-failed-to-open-truetype-font-in-matplotlib-backends-pdf-in-python stackoverflow