title: Map the values from 2 dataframe columns to a value in a dict and create a new column
body: <p>I have a dataframe which looks like below:</p>
  <pre><code>column_1 column_2
  ABC       POI
  XYZ       LOK 
  DEF       JOY
  ASD       QWE
  </code></pre>
  <p>I have a dict which has key based on <code>column_1</code> and <code>column_2</code> and different values like below:</p>
  <pre><code>d = {('ABC', 'POI'): 'Name1',
       ('XYZ', 'LOK'): 'Name2',
       ('DEF', 'JOY'): 'Name3',
       ('ASD', 'QWE'): 'Name4'}
  </code></pre>
  <p>I need to create a different column in the dataframe which maps the value of <code>column_1</code> and <code>column_2</code> from the dict to the new column. So, the resulted dataframe should look like below:</p>
  <pre><code>column_1 column_2  Result
  ABC       POI       Name1
  XYZ       LOK       Name2
  DEF       JOY       Name3
  ASD       QWE       Name4
  </code></pre>