title: How to maintain position of column data by adding blank for empty data when converting to list?
body: <p>I have data in which each row has some amount of data in up to 6 columns but not in all the columns. Sometimes the the data is in columns 3 and 4, sometimes 4 and 6, etc. I want to create a list out of each row (and extend the list to continue adding rows) and add a blank item in the list if there is no data in a column. Essentially maintaining that each row has 6 pieces of data, even if some are blank. The spacing between columns is not regular, or at least cannot be guaranteed to be regular.</p>
  <p>When each row has 6 pieces of data I have no issue since I can just join, split, and append to build my list. The issue is with rows with fewer than 6 items.</p>
  <p>See below for example data.</p>
  <pre><code>CCW40109           D+L             -0.13                         0.60
  CCW40109           4D+L+OBE                        8.77         17.38
  CCW40109           4D+L-OBE        -8.56                       -17.65
  CCW40109           4D+L+SSE                                     24.22          12.04
  </code></pre>
  <p>Here is how I want the list to look after running through every row. A single list of 24 elements with blank elements for the blank columns.</p>
  <pre><code>[CCW40109,D+L,-0.13, ,0.60, ,CCW40109,4D+L+OBE, ,8.77,17.38, ,CCW40109,4D+L-OBE,-8.56, ,-17.65, ,CCW40109,4D+L+SSE, , ,24.22,12.04]
  </code></pre>
  <p>I've been banging my head on the wall on this one. Any help is much appreciated.</p>