title: Rename specific column(s) in pandas
body: <p>I've got a dataframe called <code>data</code>. How would I rename the only one column header? For example <code>gdp</code> to <code>log(gdp)</code>?</p>
  
  <pre><code>data =
      y  gdp  cap
  0   1    2    5
  1   2    3    9
  2   8    7    2
  3   3    4    7
  4   6    7    7
  5   4    8    3
  6   8    2    8
  7   9    9   10
  8   6    6    4
  9  10   10    7
  </code></pre>