title: Pandas .isin() for list of values in each row of a column
body: <p>I have a small problem: I have a column in my DataFrame, which has multiple rows, and in each row it holds either 1 or more values starting with 'M' letter followed by 3 digits. If there is more than 1 value, they are separated by a comma.
  I would like to print out a view of the DataFrame, only featuring rows where that 1 column holds values I specify (e.g. I want them to hold any item from list ['M111', 'M222'].
  I have started to build my boolean mask in the following way:</p>
  
  <pre><code>df[df['Column'].apply(lambda x: x.split(', ').isin(['M111', 'M222']))]
  </code></pre>
  
  <p>In my mind, .apply() with .split() methods in there first convert 'Column' values to lists in each row with 1 or more values in it, and then .isin() method confirms whether or not any of items in list of items in each row are in the list of specified values ['M111', 'M222'].
  In practice however, instead of getting a desired view of DataFrame, I get error </p>
  
  <pre><code>'TypeError: unhashable type: 'list'
  </code></pre>
  
  <p>What am I doing wrong?</p>
  
  <p>Kind regards,
  Greem</p>