title: StringVar instance has no attribute 'delete'
body: <p>I am having trouble using the delete method for Entry in tkinter. Currently I import tkinter as follows:</p>
  
  <pre><code>import Tkinter as tk
  </code></pre>
  
  <p>I then declare two variables that are used to track the value of two entry fields as follows:</p>
  
  <pre><code>self.UN = tk.StringVar()
  self.PW = tk.StringVar()
  </code></pre>
  
  <p>I am able to get the value using </p>
  
  <pre><code>self.UN.get() 
  </code></pre>
  
  <p>without any issue but when try to delete the value using </p>
  
  <pre><code>self.UN.delete(0, END)
  </code></pre>
  
  <p>I get the error, StringVar instance has no attribute 'delete'
  I have looked through other possible solutions on SO but none seem relevant to my issue. I used the following tutorial to try and get this to work: <a href="http://effbot.org/tkinterbook/entry.htm" rel="noreferrer">http://effbot.org/tkinterbook/entry.htm</a></p>
  
  <p>I have also tried variations on the delete like putting Tk.END inside the brackets, but can't get this going. Any help is appreciated.</p>