[HarfBuzz] [beginner] SmallCaps and more

[moonkid at posteo.org]

I want to check if a font (e.g. FreeSans) support real small caps.
Would this be possible with harfbuzz?

Can I use harfbuzz with Python3?

background:
I waste a lot of hours with finding a font for my different XeTeX
projects. There is no font manager on linux available which fit my
needs. e.g. I want to know which of the over 6000 fonts on my
system support real small caps, or can be used with a special unicode
block (e.g. Japanese Kanji, - Hiragana, - Katakana).
Because I couldn't find a solution I currently think about writing my
own. ;)
I want so search on my local system for fonts with specific
capabilities.