dataprofessor/code ? reverse-engineered prompt

Build me a tidy set of tutorial code examples for my Data Professor style learning repo.

I want folders for common data science topics like Iris analysis, DHFR analysis, linear regression, plotting, general Python practice, Python in R, plus a couple of simple web app examples in Shiny and Streamlit. The goal is to make it easy for someone learning from scratch to open each folder and follow along with clear notebooks or scripts that show the steps, the data prep, the charts, and the model building in a simple way.

Keep it beginner friendly, well organized, and consistent across the examples. If you need to check current docs for anything, go ahead and look them up online.