title: How do I get sash_place() to work on startup?
body: <p>I have a Tkinter PanedWindow and if I use sash_place(0,50,50) with a function, it works just as desired. If, whoever, I want to place it initially, it does nothing. How can I place the sash on startup?</p>
  
  <pre><code>import Tkinter as tk
  
  def move():
      allContent.sash_place(0,100,100)
  
  root = tk.Tk()
  root.geometry("1280x720+80+50")
  
  # the toolbar
  toolBar = tk.Frame(root, bg="blue")
  toolBar.pack(anchor="nw")
  # buttons
  button_2 = tk.Button(toolBar, text="move", command=move)
  button_2.pack(side="left",)
  
  # main window
  allContent = tk.PanedWindow(root, background="red", orient="horizontal", relief="ridge", bd=5, sashrelief="raised")
  
  contentLeft = tk.Frame(allContent)
  allContent.add(contentLeft)
  
  contentRight = tk.Frame(allContent)
  allContent.add(contentRight)
  allContent.pack(fill="both", expand=1)
  
  statusBar  = tk.Label(root, text="Status")
  statusBar.pack(anchor="sw") 
  
  allContent.sash_place(0,100,100) # How do I get this to work here?
  
  root.mainloop()
  </code></pre>