def focus_by_index(self, index: int) -> None:
        """
        Change to the window at the specified index in the current group.
        """
        windows = self.windows
        if index < 0 or index > len(windows) - 1:
            return

        self.focus(windows[index])

        Change to the window at the specified index in the current group.
        
libqtile/group.py