title: Pivot table with condition
body: <p>I want to write a code to create a new dataframe based on this old dataframe using panda. 
  <a href="https://i.stack.imgur.com/wmQu5.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/wmQu5.png" alt="dataframe"></a>]</p>
  
  <p>In the image, if the field 'Address Line 1' appear more than once, copy that whole row to the new dataframe.<br>
  In the case that the field 'Address Line 1' is blank, or appear only once, do not copy. </p>
  
  <p>Notes: Multiple rows entries that has the same 'Address Line 1' might not be right next to each other.</p>