title: How do I turn categorical column values into different column names?
body: <p>I'm not sure how to approach this problem since I'm a beginner with pandas.</p>
  <p>I have this dataframe:</p>
  <pre><code>  col1 col2
  0    a    1 
  1    a    2 
  2    a    3 
  3    b    4
  4    b    5
  5    b    6
  6    c    7
  7    c    8
  8    c    9
  </code></pre>
  <p>and I want to turn it into a dataframe or a matrix like this:</p>
  <pre><code>   cola colb  colc
  0    1    4    7
  1    2    5    8
  2    3    6    9
  </code></pre>
  <p>How should I approach this in Python?</p>