title: How to get all rows by joining 2 dataframes
body: <p>I have 2 dataframes:</p>
  <pre><code>Location    Places  Date        Date_part   Sector      Category    units   
  USA         Place_1 7/1/2021    7/1/2021    Cars        Passenger   200
  IND         Place_2 7/1/2021    7/1/2021    Cars        Passenger   180     
  COL         Place_3 7/1/2021    7/1/2021    Trucks      Goods       100
  </code></pre>
  <pre><code>Location    Places      Clicks        
  USA         Place_1     320       
  COL         Place_3     730       
  CAN         Place_4     84        
  
  </code></pre>
  <p>I need to create a new dataframes like this</p>
  <pre><code>Location    Places  Date        Date_part   Sector      Category    units   ClicksPerDay   
  USA         Place_1 7/1/2021    7/1/2021    Cars        Passenger   200     320
  IND         Place_2 7/1/2021    7/1/2021    Cars        Passenger   180     
  COL         Place_3 7/1/2021    7/1/2021    Trucks      Goods       100     730
  CAN         Place_4 7/1/2021    7/1/2021    Cars        Passenger           84
  </code></pre>
  <p>I need ClicksPerDay column to be created from Clicks and value to be available where ever Sector= Cars and Category=Passenger</p>
  <p>I tried using
  <code>df_result = df1.unionByName(df2)</code></p>
  <p>But I need to achieve this by joining 2 dataframes. The result dataframe should be having all rows from both dataframes
  Please share any other approaches.</p>