title: Python Pandas DateOffset using value from another column
body: <p>I was thinking this would be very easy but the below is not working for what I want. Just trying to compute a new date column by adding days to a pre-existing datetime column using values from another column. My 'offset' column below just has 1 digit numbers.</p>
  
  <pre><code>df['new_date'] = df['orig_date'].apply(lambda x: x + pd.DateOffset(days=df['offset']))
  </code></pre>
  
  <p>Error: <code>unsupported type for timedelta days component: Series</code></p>
  
  <p>thank you,</p>