title: Retrieving the list of references to an object in Python
body: <p>All:</p>
  
  <pre><code>a = 1
  b = a
  c = b
  </code></pre>
  
  <p>Now I want to get a list of object <code>1</code> tagged, which is <code>[a, b, c]</code>. How could I do this?</p>
  
  <p>BTW, how to call variable "a" here officially? I know so far it is a "object tag" for the object, but I have no idea what is the term of it.</p>
  
  <p>Thanks!</p>
  
  <p>why do I need this:</p>
  
  <pre><code>a = b = c = 1 
  print a, b, c 
  1 1 1
  a = 2
  print a, b, c 
  2 1 1
  </code></pre>
  
  <p>in other language such as C, a,b,c should be 2 if I re-assign a = 2, but in python, there's no such thing like reference, so the only way to change all the value of a b c is a = b = c = 2 so far as I know, that is why purposed to get all reference of an object.</p>