title: How to replace empty string with zero in comma-separated string?
body: <p>"8,5,,1,4,7,,,,7,,1,9,3,6,,,8,6,3,9,,2,5,4,,,,,3,2,,,7,4,1,1,,4,,6,9,,5,,,,5,,,1,,6,3,,,6,5,,,,7,4,,1,7,6,,,,8,,5,,,7,1,,3,9,"</p>
  
  <p>I'm doing a programming challenge where i need to parse this sequence into my sudoku script.
  Need to get the above sequence into 8,5,0,1,4,7,0,0,0,7,0,1,9,3,6,0,0,8.........
  I tried re but without success, help is appreciated, thanks.</p>