title: Compare list of 2 columns in a python dataframe and count the same item
body: <p>how to compare list of 2 columns in a python dataframe and count the same list between these 2 column in a dataframe. For example:</p>
  <pre><code>column A            |   column B
  ====================================
  ['a', 'b', 'c']     | ['a', 'b']
  ['a', 'b']          | ['a']
  ['b']               | ['a']  
  </code></pre>
  <p>i want to get this result:</p>
  <pre><code>    column A            |   column B    | count_same_item
      ======================================================
      ['a', 'b', 'c']     | ['a', 'b']    | 2
      ['a', 'b']          | ['a']         | 1
      ['b']               | ['a']         | 0
  </code></pre>
  <p>really appreciate any help</p>