class tkinter.ttk.Treeview
bbox(item, column=None)
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.
get_children(item=None)
Returns the list of children belonging to item. If item is not specified, returns root children.