title: How to turn a pandas dataframe row into a comma separated string
body: <p>I need to iterate over each row of a pandas df and turn this into a comma separated string.</p>
  
  <p>example:</p>
  
  <pre><code>df3 = DataFrame(np.random.randn(10, 5),
                columns=['a', 'b', 'c', 'd', 'e'])
  
  
            a         b         c         d         e
  0 -0.158897 -0.749799  0.268921  0.070035  0.099600
  1 -0.863654 -0.086814 -0.614562 -1.678850  0.980292
  2 -0.098168  0.710652 -0.456274 -0.373153 -0.533463
  3  1.001634 -0.736187 -0.812034  0.223062 -1.337972
  4  0.173549 -0.576412 -1.016063 -0.217242  0.443794
  5  0.273695  0.335562  0.778393 -0.668368  0.438880
  6 -0.783824  1.439888  1.057639 -1.825481 -0.770953
  7 -1.025004  0.155974  0.645023  0.993379 -0.812133
  8  0.953448 -1.355628 -1.918317 -0.966472 -0.618744
  9 -0.479297  0.295150 -0.294449  0.679416 -1.813078
  </code></pre>
  
  <p>I'd like to get for each row:</p>
  
  <pre><code> '-0.158897,-0.749799,0.268921,0.070035,0.099600'
   '0.863654,-0.086814,-0.614562,-1.678850,0.980292'
  ... and so on
  </code></pre>