title: Adding attribute from the different table with Pandas
body: <p>I am using Pandas to process table.</p>
  
  <pre><code>[table1]
    sample1 sample2 sample3
  A 11      22      33
  B 1       2       3
  
  [table2]
    sample3 sample4 sample2
  D 333     444     222
  
  [Result]
    sample1 sample2 sample3
  A 11      22      33
  B 1       2       3
  D NaN     222     333
  </code></pre>
  
  <p>I have two tables, and I want to add row <code>D</code> (of table 2) to table 1, considering the column name. If the column in table 1 exists in table 2, the corresponding value of <code>D</code> is added to table 1, like sample 2 and sample 3. If the column in table does not exist in table 2 like sample 1, the value of D is set to <code>NaN</code> or ignored.</p>
  
  <p>Is there any simple way to do this with Pandas?</p>