How to add metadata info to a DataFrame?

[ScottPJones]

I hope that whatever approach to metadata is taken, that it is as generic as possible (which seemed to be the case in some of the above proposals), and that it can keep track of more than one source of metadata (i.e. one from the database, for display labels, etc.). Trying to merge them would be a difficult problem, I think it’s better to be able to handle different sorts from the start.

@tk3369

Consider the case of reading data from a relational database. Each column has metadata like data type, length, precision, allow nulls, etc. Often these are good information that is very handy when processing query results.

@pdeffebach

I think this essentially means that whatever metadata we have has to have at least two types, one for “nice” labels that are to be displayed and another that shows stuff about the variable that the user of a dataset needs to know. Stata handles this via a label' metadata category and a notes’ metadata category.