title: Pandas: print column name with missing values
body: <p>I am trying to print or to get list of columns name with missing values. E.g.   </p>
  
  <pre><code>data1 data2 data3  
  1     3     3  
  2     NaN   5  
  3     4     NaN  
  </code></pre>
  
  <p>I want to get ['data2', 'data3'].
  I wrote following code:</p>
  
  <pre><code>print('\n'.join(map(
      lambda x : str(x[1])
      ,(filter(lambda z: z[0] != False, zip(train.isnull().any(axis=0), train.columns.values)))
  )))
  </code></pre>
  
  <p>It works well, but I think should be simpler way.</p>