def column_keymap(self):
        """ Returns keymap and keystates used in column mode """
        keystates = set()

        shortcuts = self.cp.items('column_keymap')
        keymap_dict = dict(shortcuts)

        for combo, action in shortcuts:
            # add all possible prefixes to keystates
            combo_as_list = re.split('(<[A-Z].+?>|.)', combo)[1::2]
            if len(combo_as_list) > 1:
                keystates |= set(accumulate(combo_as_list[:-1]))

            if action in ['pri', 'postpone', 'postpone_s']:
                keystates.add(combo)

            if action == 'pri':
                for c in ascii_lowercase:
                    keymap_dict[combo + c] = 'cmd pri {} ' + c

        return (keymap_dict, keystates)
Returns keymap and keystates used in column mode