support ttc fonts #8612

I am trying to use Chinese text in my plot. There are some pre-installed font on the system which support Chinese (using fc-list :lang=zh), for example "WenQuanYi Zen Hei". But I find that these fonts can not be found by matplotlib. I checked some of the code of font_manager. I find that font_manger seems intentionally avoid finding font files in ttc extensions.

In order to use these font, I have to explicitly give the path of the font, like the following example code:

import matplotlib.pyplot as plt
import matplotlib.font_manager as mfm
ch_font = mfm.FontProperties(fname="/usr/share/fonts/wqy-zenhei/wqy-zenhei.ttc")
plt.annotate(xy=(0.5, 0.5), s=u'测试', xycoords='axes fraction', fontproperties=ch_font)
plt.show()

What is the reason behind this ?

Matplotlib version

• Operating System: CentOS 7.2
• Matplotlib Version: 2.0.1
• Python Version: 3.6