The original Collection Hole Finder tool, updated for ComicBase 2020 and later
Collection Hole Finder came about as effort to enhance ComicBase's ability to list issues missing from a collection (essentially, issues having a Quantity value of 0). While the ComicBase Issue Checklist report applied to missing issues is useful, it is often overwhelmingly large, especially when considering some older titles, such as Action Comics. While any collector will determine that any missing issue is a hole that needs to be filled, I determined that a pragmatic solution was needed, and decided that I would focus on filling holes of finite size.
What is a hole? A hole is a grouping of missing issues between issues owned. For example, if I own issues 1 and 5, then the hole is issues 2-4. I settled on a hole size of 5 issues or less. If I own issues 1 and 5, then I'd try to buy issues 2, 3, and 4 eventually. However, if I own issues 1 and 7, then forget about issues 2-6.
Once that decision was made, I could export the missing issues checklist just for those titles I had "in stock" into a spreadsheet and start deleting issues that didn't fit into a small enough hole. However, that still meant whittling a report of thousands of issues down to one of tens of issues by hand. Since I'm a programmer for a living, it seemed natural to create a program to parse the text file output from ComicBase. And so, Collection Hole Finder was born.
Later on, in the ComicBase forums, others posted with similar frustrations, and it was requested that Collection Hole Finder be shared with other collectors. I was encourage to share the source code with the users, in the hopes that they could recommend (or even code up) enhancements to the program. Please see the "Contact" section to recommend enhancements or share changes.