title: Split String In List While Preserving Original List Order
body: <p>I would like to do something a bit tricky and I'm not sure the best way to go about it.</p>
  
  <p>I have a two dimensional array that is in the form a nested list. Each "Row" in the list has the following structure:</p>
  
  <pre><code>['171000', 'Thing..Mega~Corporate~Thing..Mid~Dairy~Thing..Micro~Cheese', 'Cheese', '0.012174']
  </code></pre>
  
  <p>What I would like to do is loop through the entire array, row by row, and create a new row that splits the string in the second position into three new strings in the list so the result is as follows:</p>
  
  <pre><code>['171000', 'Mega~Corporate', 'Mid~Dairy', 'Micro~Cheese', 'Cheese', '0.012174']
  </code></pre>
  
  <p>A couple things I have to mention. In the above case, I split the string into three sub strings, Mega, Mid, Micro. Not every string will have a "Mid" and a "Micro" portion of it. Some of these strings could simply be shorter versions of the same format:</p>
  
  <pre><code>'Thing..Mega~Corporate'
  </code></pre>
  
  <p>For this case, I'd like to insert a placeholder to preserve the position of each element in the array (so that the numbers in the final position always have the same index).</p>
  
  <p>The array I'm working with is rather large, upwards of 100k rows. Any help would be greatly appreciated as I'm really struggling with this one.</p>