add a way to "load" a file displayed in the explorer as a variable

[gdementen]

• always as Array? or Session?
• theoretically, we could write a generic loader using the adapters which return a 2D Array (most likely of object dtype)
  • each label column would become one label in the second axis
  • while this would be nifty, I am unsure it would be that useful in practice
• for smallish dataset we could compute the cartesian_product of labels
  • this would be a lot more useful but absolutely requires a check to avoid trying to load structure where the cartesian product would not fit in memory (e.g. large dataframe-with-multi-index structures).
• what we really need is a way to load the formats we wrote ourselves/which can be loaded currently (.h5, directory of .csv and .xlsx)

[gdementen]

Duplicate of #304. My memory is really bad 😢.

[gdementen]

The last point (loading our own format) is technically very easy: it is just adding an UI element to do Session(<path_variable>).to_globals(). The difficulty is how to present that and how to convey which files can be loaded and which cannot. I think the ideal solution would be a second column in the variable list with a "Load" button (but then the variable list will become very messy). Or maybe as a context menu action?