title: Create matrix from simple pandas dataframe
body: <p>I have a simple dataframe with two columns and would like to transform it into a matrix with same number of columns and rows.</p>
  
  <p>I have several combinations as rows and would like to copy those into columns in order to have a view of the strength of the relationships on a visual level (possibly a chord diagram).</p>
  
  <p>This is a sample the dataframe I'm using:</p>
  
  <pre><code>variables         count
  a                  13
  b                   9
  c                   8
  d                   6
  e                  10
  f                  12
  g                   9
  h                   7
  a_b                 7
  a_b_h               8
  </code></pre>
  
  <p>And this is the output I would like to have, taking into account that I have several combinations, not just pair wise.</p>
  
  <pre><code>         a  b  c  d  e  f  g  h  a_b a_b_h
  a       13  7  0  0  0  0  0  0  0    0
  b        7  9  0  0  0  0  0  0  0    0
  c        0  0  8  0  0  0  0  0  0    0
  d        0  0  0  6  0  0  0  0  0    0
  e        0  0  0  0 10  0  0  0  0    0
  f        0  0  0  0  0 12  0  0  0    0
  g        0  0  0  0  0  0  9  0  0    0
  h        0  0  0  0  0  0  0  7  0    0
  a_b      0  0  0  0  0  0  0  0  7    0
  a_b_h    0  0  0  0  0  0  0  0  0    8
  </code></pre>
  
  <p>And so on, with all the combinations.</p>
  
  <p>The aim is to then build a chord diagram like the one below - which shows the strength of the relationships between variables</p>