title: How to obtain Column Names having NAN values using PANDAS and store those column names in a List?
body: <p>I have a data frame as below,</p>
  <pre><code>df = pd.DataFrame({'A': [1, 2, 3, 4, 5],
                'B': [1, Nan, 2, 3, 4],
                'C': [2, 3, Nan, Nan,5],
                'D': [5, 6, 6, 7, 8],
                'E': [Nan, 2, 3, 4, 5]})
  
     A  B     C     D     E       
  0  1  1     2     5     Nan       
  1  2  Nan   3     6     2  
  2  3  2     Nan   6     3  
  3  4  3     Nan   7     4  
  4  5  4     5     8     5
  </code></pre>
  <p>Here I am using <code>df.dropna(axis=1,inplace=True)</code> to drop columns having <code>NAN</code> in the data frame.
  But before dropping those columns I need to capture the columns which are having <code>NAN</code> values and store those column names in List.</p>
  <p>eg: In the above data frame we have <code>NAN</code> in B,C and E columns. So those column names have to be stored in the list first [B,C,E] and then drop all those columns.</p>
  <p>Any suggestions on how to store those column names in a list?</p>