group by property

[perfringo]

As in my initial post, I want the result as like:

I asked why you want result like that? What are the benefits of new structure over old one?

old = [{'name': 'John', 'm': 'good', 'n': 1},
       {'name': 'Alina','m': 'good', 'n': 1},
       {'name': 'Olivia', 'm': 'bad', 'n': 2},
       {'name': 'Ruby', 'm': 'bad','n': 2}]

new = [{'g': [{'name': 'John', 'n': 1}, {'name': 'Alina', 'n': 1}]},
       {'b': [{'name': 'Olivia','n': 2},{'name': 'Ruby','n': 2}]}]

Old list dictionaries have exactly the same structure, new list dictionaries not (some have key 'g', some key 'b' and some probably both). You must be extra careful to not run into KeyError while accessing data.