title: matplotlib: using a colormap to color table-cell background
body: <p>I have a Pandas dataframe, and i want to plot it as matplotlib table. So far i have that part working with following code:</p>
  
  <pre><code>import numpy as np
  randn = np.random.randn
  from pandas import *
  
  idx = Index(arange(1,11))
  df = DataFrame(randn(10, 5), index=idx, columns=['A', 'B', 'C', 'D', 'E'])
  vals = np.around(df.values,2)
  
  fig = plt.figure(figsize=(15,8))
  ax = fig.add_subplot(111, frameon=True, xticks=[], yticks=[])
  
  the_table=plt.table(cellText=vals, rowLabels=df.index, colLabels=df.columns, 
                      colWidths = [0.03]*vals.shape[1], loc='center')
  
  table_props = the_table.properties()
  table_cells = table_props['child_artists']
  
  clm = cm.hot(vals)
  
  for cell in table_cells: 
      cell.set_height(0.04)
      # now i would like to set the backgroundcolor of the cell
  </code></pre>
  
  <p>At the end of this i would like to set the background-color of the cell according to the colormap - but how do i look it up in the clm array without an index?</p>
  
  <p>Another question: can i somehow pass a format string to the table, so that it formats the text to 2 decimal places?</p>
  
  <p>Any hints appreciated,
  Andy</p>