ttk Treeview: How to select a row?

This must be something simple I'm missing, but I can't seem to figure out how to set the selection row in a Treeview using the `selection_set` method. I am confused by the ttk documentation which sometimes refers to `items` and other times to `iid` for method arguments. When I insert a row into the `Treeview`, am I not creating an item which I give the handle `iid`? ``` import Tkinter as Tk import ttk root = Tk.Tk() tree = ttk.Treeview(root, displaycolumns='#all') tree["columns"]=("1", "2", "3", "4") tree.column("#0", width=70) tree.column("1", width=70, anchor=Tk.CENTER) tree.column("2", width=50, anchor=Tk.CENTER) tree.column("3", width=50, anchor=Tk.CENTER) tree.column("4", width=70, anchor=Tk.CENTER) tree.heading("1", text="Column 1") tree.heading("2", text="Column 2") tree.heading("3", text="Column 3") tree.heading("4", text="Column 4") id2 = [] count = 0 item_list = ['A', 'B', 'C', 'D'] for item in item_list: id = tree.insert("", count, iid='Row %s'%count, text=item, values=('1', '2', '3', '4')) id2.append(id) count += 1 tree.selection_set('Row 0') # Doesn't work -- returns "_tkinter.TclError: Item Row not found" tree.pack(fill=Tk.BOTH, expand=1, side=Tk.RIGHT,padx=50) Tk.mainloop() ``` Traceback: ``` Traceback (most recent call last): File "python-ttk-treeview-how-to-select-a-row.py", line 28, in <module> tree.selection_set('Row 0') # Doesn't work -- returns "_tkinter.TclError: Item Row not found" File "C:\Python\lib\lib-tk\ttk.py", line 1402, in selection_set self.selection("set", items) File "C:\Python\lib\lib-tk\ttk.py", line 1397, in selection return self.tk.call(self._w, "selection", selop, items) _tkinter.TclError: Item Row not found ```