title: Conditional formatting for 2- or 3-scale coloring of cells of a table
body: <p>I would like to output a simple table to a PDF file with some conditional formatting of 2- or 3-scale coloring of cells dependent on the value. Like the red-white-green color scaling in Microsoft Excel conditional formatting option.</p>
  
  <pre><code>import pandas
  import numpy as np
  df = pandas.DataFrame(np.random.randn(10, 2), columns=list('ab'))
  print df
  
  #Output:
            a         b
  0 -1.625192 -0.949186
  1 -0.089884  0.825922
  2  2.117651 -0.046258
  3 -0.921751 -0.144447
  4 -0.294095 -1.774725
  5 -0.780523 -0.435909
  6  0.544958  0.303268
  7  0.014335  0.036182
  8 -0.756565  0.120711
  9  1.145055  0.542755
  </code></pre>
  
  <p>Now, I would like to output this to a PDF in a table with a 3-scale conditional format for column <code>a</code> and independently for column <code>b</code> so my output would look like the below example from Excel.</p>
  
  <p>Kind of like this, but by column:
  <img src="https://i.stack.imgur.com/8EzOd.jpg" alt="enter image description here"></p>