There is one directory per dataset.
Each directory contains the original data (if small enough), a Jupyter Notebook
or Python .py script or R Notebook or .R script to process the data, and
a directory processed with new copies of the data as output from the notebook
/ script.
The Jupyter notebooks are in native .ipynb format, and in .Rmd RMarkdown
format, for ease of editing and version control.
I use the excellent Jupytext to interact with the RMarkdown versions of the files.
See the README.md file in each directory for license / copyright of the files
in that directory.
See data_links.md for links at which to search for datasets.