title: Mapping columns from one dataframe to another to create a new column
body: <p>i have a dataframe</p>
  
  <pre><code>id  store    address
  1    100        xyz
  2    200        qwe
  3    300        asd
  4    400        zxc
  5    500        bnm
  </code></pre>
  
  <p>i have another dataframe df2</p>
  
  <pre><code>serialNo    store_code  warehouse
      1          300         Land
      2          500         Sea
      3          100         Land
      4          200         Sea
      5          400         Land
  </code></pre>
  
  <p>I want my final dataframe to look like:</p>
  
  <pre><code>id  store    address  warehouse
  1    100        xyz     Land
  2    200        qwe     Sea
  3    300        asd     Land
  4    400        zxc     Land
  5    500        bnm     Sea
  </code></pre>
  
  <p>i.e map from one dataframe onto another creating new column</p>