title: Regarding the immutability of pandas dataframe indexes
body: <p>I read in the documentation that the index objects are immutable and can not be changed once created. But I can change the values after creation. </p>
  
  <p>Am I missing something here?</p>
  
  <p>This is what I tried:</p>
  
  <pre><code>ser = pd.Series([5,0,3,8,4], index=['red','blue','yellow','white','green'])
  ser
  
  red       5
  blue      0
  yellow    3
  white     8
  green     4
  dtype: int64
  
  ser.index = ['red','blue','yellow','white','test']
  ser
  
  red       5
  blue      0
  yellow    3
  white     8
  test      4
  dtype: int64
  </code></pre>