title: Change Values in pandas dataframe column
body: <p>I have a dataframe filled with several columns. I need to change the values of a column for data normalization like in the following example:</p>
  
  <pre><code>User_id   
  751730951     
  751730951
  0
  163526844
  ...and so on
  </code></pre>
  
  <p>I need to replace every value in the column that is not 0 (string) in a into something like "is not empty". I have tried it now for hours but still cannot change every value that is not 0 into something else. Replace()-function don't work really good for that. Some good ideas?</p>
  
  <p>EDIT (my solution):</p>
  
  <pre><code>finalResult.loc[finalResult['update_user'] == '0', 'update_user'] = 'empty'
  finalResult.loc[finalResult['update_user'] != 'empty', 'update_user'] = 'not empty'
  </code></pre>