title: Pandas - Check if column of strings in column of lists row wise
body: <p>I have a dataframe which you can build with this:</p>
  
  <pre><code>dflist=[['123',['abc','qw3','123']],
          ['ab12',['3e4r5','12we3','asd23','q2w3']]]
  df=pd.DataFrame(dflist,columns=['check','checklist'])
  </code></pre>
  
  <p>And looks like this:</p>
  
  <pre><code>  check                    checklist
  0   123              [abc, qw3, 123]
  1  ab12  [3e4r5, 12we3, asd23, q2w3]
  </code></pre>
  
  <p>I want to check if the item in column "check" is in the list in column "checklist".  So I want the resulting dataframe to look like:</p>
  
  <pre><code>  check                    checklist checkisin
  0   123              [abc, qw3, 123]      True
  1  ab12  [3e4r5, 12we3, asd23, q2w3]     False
  </code></pre>
  
  <p>I have tried several things including using .isin in various forms including apply/lambda.  and directly. </p>
  
  <p>This:</p>
  
  <pre><code>df['checkisin']=df.check.isin(df.checklist)
  </code></pre>
  
  <p>produces:</p>
  
  <pre><code>  check                    checklist  checkisin
  0   123              [abc, qw3, 123]      False
  1  ab12  [3e4r5, 12we3, asd23, q2w3]      False
  </code></pre>
  
  <p>which has two Falses.</p>
  
  <p>Trying this:
  df['checkisin']=df.apply(lambda x:x.check.isin(x.checklist))
  gives this error:</p>
  
  <pre><code>AttributeError: ("'Series' object has no attribute 'check'", 'occurred at index check')
  </code></pre>
  
  <p>Trying this:</p>
  
  <pre><code>df['checkisin']=df.apply(lambda x:x['check'] in x.checklist)
  </code></pre>
  
  <p>gives this error:</p>
  
  <pre><code>KeyError: ('check', 'occurred at index check')
  </code></pre>
  
  <p>I'm sure I'm missing something simple here.  I know I could loop this, but looking for a Pandas Dataframe column wise solution as the DF I have is very large and trying to "most" efficiently handle.  </p>
  
  <p>Thanks!</p>