title: How to clear items from a ttk.Treeview widget?
body: <pre><code>ing_scroll = Scrollbar(window1_frame1, orient=VERTICAL)
  ingredients = ttk.Treeview(window1_frame1, yscrollcommand=ing_scroll.set, height=5, columns=['Ingredient', 'Amount'], show="headings")
  ingredients.heading("Ingredient", text='Ingredient')
  ingredients.column("Ingredient", width=7)
  ingredients.heading("Amount", text='Amount')
  ingredients.column("Amount", width=1)
  ing_scroll.config(command=ingredients.yview)
  ing_scroll.pack(side=RIGHT, fill=Y)
  ingredients.pack(side=LEFT, fill='both', expand=1)
  
  def OnRecpSelect(event):
      DB = menu_combo.get()
      mytable = recipe_combo.get()
      ingredient_list = TKengine.pull_ingredients(DB, mytable)
      # NEED TO CLEAR THE INGREDIENTS TTK:TREEVIEW OBJECT HERE!
      for i in ingredient_list: 
          ingre = i[1]
          amoun = i[2]
          value = ingre,amoun
          ingredients.insert('',0,values=value)
  </code></pre>
  
  <p>ingredient_list is a list that displays something like... ('Sugar', '1 Cup') and so on...  The def is for a combobox that is selected, so what I would like is for the treeview to clear and not just keep adding more ingredients.  Unfortunately I don't see a <code>clear()</code> method.</p>
  
  <p>If theres a programmatic way of identifying what is there first (enumerating a rowcount would be good...)  this is driving me nuts.  I did notice in the docs that you can use the delete method, but it wants to know what the item is to delete... if I use:</p>
  
  <pre><code>ingredients.delete('',0)
  </code></pre>
  
  <p>I get </p>
  
  <pre><code>TclError: Item 0 not found
  </code></pre>
  
  <p>So I would assume it wants something like 'Sugar' as the Item... </p>
  
  <p>of course its a catch 22 because if you select the combobox and want to clear the ingredients treeview, the same ingredient items are not in every recipe, so how do we know what items to delete?...  </p>
  
  <p>Please let me know if you need any more details... I am fairly new to working with the treeview object, but its making me want to just work with two listboxes on a canvas.</p>