a group_by option

[ctomkow]

Provide a group_by parameter for the methods to return the found values as part of a two dimensional list. Each found value part of the same dict will be returned as a list. Multiple lists will be returned within a list.

The new find_keys() function currently returns a 2d list. The default behaviour should be changed to return a simple list, and return a 2d list if the group_by parameter is True. The parameter should have a default of False.

[ctomkow]

You can pass the keyword parameter group=False to find_keys() to return a one dimensional list. https://github.com/ctomkow/jsonparse/commit/bead1efdcde1069f200c8b897c72304dde4b6de0