title: How to rename pandas dataframe column name by checking columns's data
body: <p>Example df would be:</p>
  
  <pre><code>   a         b  c  d   e
  0  SN123456  3  5  7   SN123456
  1  SN456123  4  6  8   SN456123
  </code></pre>
  
  <p>I am wondering how I can rename the column name from 'a' to 'Serial_Number' base on the data -- it starts with 'SN' and length is fix:8. </p>
  
  <p>(we may not know the name of 'a' as it read from some csv file, also the position is not known)</p>
  
  <p>Also how to remove duplicated column 'e', it's completely duplicated with column 'a'</p>
  
  <p>Any idea on a faster way?
  Loop each column serial and get it's index and rename column's name is somehow not a good method.
  Thanks!</p>