title: How to perform an operation on specific columns within pandas dataframe while preserving other columns
body: <p>I am trying to perform an operation on all columns within my pandas dataframe except one. </p>
  
  <p>I first tried:</p>
  
  <pre><code>df=df[:,1:]*0.001
  </code></pre>
  
  <p>returned an error message. Then tried:</p>
  
  <pre><code>df=df.iloc[:,1:]*0.001
  </code></pre>
  
  <p>I want the operation to be performed on all columns except the first one. However, this replaces the dataframe with only the columns I have selected for the operation.</p>
  
  <p>How do you select specific columns to perform operations while leaving others unaltered? I may have situations where it is not necessarily the first column to remain untouched.</p>
  
  <p>Thanks.</p>