'Returns the bounding box (relative to the treeview widget\'s
window) of the specified item in the form x y width height.
If column is specified, returns the bounding box of that cell.
If the item is not visible (i.e., if it is a descendant of a
closed item or is scrolled offscreen), returns an empty string.'

def bbox(self, item, column=None):

    return (self._getints(self.tk.call(self._w, 'bbox', item, column)) or '')
