Tee Sorting

    def sort(self, col, reverse):

        def do_sort(_col, _reverse):
            if col != '#0':
                _data = [(self.set(k, col), k) for k in self.get_children()]
            else:
                _data = [(self.item(k)['text'], k) for k in self.get_children()]

            _data.sort(reverse=reverse)
            for _index, (_value, _parent) in enumerate(_data):
                self.move(_parent, '', _index)

        self.heading(col, command=lambda: do_sort(col, not reverse))

        def walk(children):
            for child in children:
                if col != '#0':
                    data = [(self.set(k, col), k) for k in self.get_children(child)]
                else:
                    data = [(self.item(k)['text'], k) for k in self.get_children(child)]

                data.sort(reverse=reverse)
                for index, (val, parent) in enumerate(data):
                    self.move(parent, child, index)
                    if self.get_children(child):
                        walk(self.get_children(child))

        walk(self.get_children())