title: Python: copy of a variable
body: <p>Is there a way in to make copy of a variable so that when the value changes of variable 'a' it copies itself to variable 'b'?</p>
  
  <p>Example</p>
  
  <pre><code>a='hello'
  
  b=a     #.copy()  or a function that will make a copy
  
  a='bye'
  
  # Is there a way to make 
  # 'b' equal 'a' without 
  # doing 'b=a'
  
  print a
  print b
  </code></pre>
  
  <p>I am having a problem using the Tkinter library where I have checkbutton that has been stored in a list and I'm trying to get the variable that it holds.</p>
  
  <p>But it takes around <strong>5 lines of code</strong> to reach the variable. </p>
  
  <h3>Is there a way of holding a copy of the variable that changes when the checkbutton variable changes?</h3>