I'm very satisfied with my homebrew Python finance plotting library, finplot, which has served me well and has a nice and clean api - plus it's pretty stable. Thus I pip-ified it in hope someone else will put it to good use.
This is what a minimal example looks like:
Auto-zoom-scale/-pan, crosshair, measuring and snap included among other things. Pretty sweet, huh?
Ventures of an ex indie game developer