title: Applying function to Pandas dataframe by column
body: <p>I have a function which I want to apply to certain columns of a pandas dataframe. 
  So rather than explicitly stating the columns, I want to dynamically select the columns I want and then call the function e.g.</p>
  
  <p>How to implement something like:</p>
  
  <pre><code>for column in dataframe:
      if column.name != 'manager':
         apply function():
  </code></pre>