Flatten dicts of dicts in DataFrame

[rocco_sprmnt21]

@stene

Albeit it will not work on some JSON data, since keys might be missing. On a more complicated case I got:
KeyError: key “xxxx” not found. Will report a separate bug, since the intention of the feature is great. A ready made feature was what I was looking for.

Maybe there is something here that (suitably adapted) could be useful for you. Can you provide some minimal but exhaustive examples of the cases that interest you?