title: Why can't you modify attribute of a row directly in pandas
body: <p>Lets say I have a dataframe A with attribute called 'score'.
  I can modify the 'score' attribute of the second row by doing:</p>
  <pre><code>tmp = A.loc[2]
  
  tmp.score = some_new_value
  
  A.loc[2] = tmp
  </code></pre>
  <p>But I cant do it like this:</p>
  <pre><code>A.loc[2].score = some_new_value
  </code></pre>
  <p>Why ?</p>