@register(u'backward-char')
def backward_char(event):
 buff = event.current_buffer
 buff.cursor_position += buff.document.get_cursor_left_position(count=event.arg)

@ register ( u'backward-char' ) def backward_char ( event ) : buff = event . current_buffer buff . cursor_position += buff . document . get_cursor_left_position ( count = event . arg )
move back a character .