From a cursory glance at both projects, it looks like plotnine doesn't do interactivity, for a start?

I wonder why they decided to start from scratch in Kotlin rather than just add the interactivity feature to plotnine. Now we have two competing projects...

I'm a big fan of Plotnine and recommend it to anyone who will listen.

My (wildly speculative) guess for the motivations behind this library would be that Kotlin, as a base, is usable in the other JetBrains IDE's, e.g. reusing the same library and grammar when developing in Java or Ruby.

I'm pretty sure that there have been multiple attempts to recreate ggplot in python.

I can think of 3-4 off the top of my head.

AFAIK plotnine is the only one with substantial adoption (2.3k stars on github) and active development for several years.

Would be curious to hear which ones you're thinking of (since I wouldn't be surprised if the are others, but also am guessing no others hit both points)

Honestly, I've definitely seen at least 3-4 attempts hit HN over the past nine years or so.

Plotnine is the only one another human has told me about, though.

Altair does Grammar of Graphics and interactivity, and has ~6k stars.