grouping and sorting within groups using another list

[Larry Martell]

On Wed, Sep 2, 2020 at 11:22 AM David Raymond <David.Raymond at tomtom.com> wrote:
>
> Would it be something as simple as:
>
> rows.sort(key = lambda x: (x[0], x[3], x[4], sort_list.index(x[6])))

This is perfect - thanks!


> -----Original Message-----
> From: Python-list <python-list-bounces+david.raymond=tomtom.com at python.org> On Behalf Of Larry Martell
> Sent: Wednesday, September 2, 2020 1:55 PM
> To: Python <python-list at python.org>
> Subject: grouping and sorting within groups using another list
>
> I have a list of tuples, and I want to group them by 3 items (0, 3, 4)
> and then within each group sort the data by a 4th item (6) using a
> sort order from another list. The list is always ordered by the 3
> grouping items.
>
> For example, if I have this list:
> rows =
> [('a', 'b', 'c', 'd', 'e', 'f', 'blue', ....),
>  ('a', 'x', 'y', 'd', 'e', 'f', 'green', ....),
>  ('a', 'q', 'w', 'd', 'e', 'f', 'white', ....),
>  ('p', 'x', 'y', 'd', 'e', 'f', 'white', ....),
>  ('p', 'x', 'y', 'd', 'e', 'f', ' 'blue', ...),
>  ('p', 'x', 'y', 'd', 'e', 'f', ' 'green', ...),
>  ('z', 'x', 'y', 'm', 'n', 'o', 'green, ...),
>  ('z', 'x', 'y', 'm', 'n', 'o', 'white, ...),
>  ('z', 'x', 'y', 'm', 'n', 'o', 'blue, ...),
> ]
>
> and I have a list:
>
> sort_list = ['blue', 'white', 'green']
>
> Then the result list would be:
>
> [('a', 'b', 'c', 'd', 'e', 'f', 'blue', ....),
>  ('a', 'x', 'y', 'd', 'e', 'f', 'white', ....),
>  ('a', 'q', 'w', 'd', 'e', 'f', 'green', ....),
>  ('p', 'x', 'y', 'd', 'e', 'f', 'blue', ....),
>  ('p', 'x', 'y', 'd', 'e', 'f', ' 'white', ...),
>  ('p', 'x', 'y', 'd', 'e', 'f', ' 'green', ...),
>  ('z', 'x', 'y', 'm', 'n', 'o', 'blue, ...),
>  ('z', 'x', 'y', 'm', 'n', 'o', 'white, ...),
>  ('z', 'x', 'y', 'm', 'n', 'o', 'green, ...),
> ]
>
> Been trying to do with using groupby but have not been successful.