title: intersect dataframes python, keep one dataframe columns
body: <p>I would like to join 2 dataframes, so that the result will be the intersection on the two datasets on the key column.
  By doing this:</p>
  
  <pre><code>result = pd.merge(df1,df2,on='key', how='inner')
  </code></pre>
  
  <p>I will get what I need, but with extra columns of df2. I only want df1 columns in the results. (I do not want to delete them later).</p>
  
  <p>Any ideas?</p>
  
  <p>Thanks,</p>