Thanks for taking the time, graff.

As you suggested, I printed out the keys for %locations (with ":" as delimiter). There are 10 keys, none of them is an empty string and that doesn't change throughout the loop.

I didn't mention before that I've also put the chromosome search before the keyword search. I get the same problem for the chromosome search only so I'm guessing it must be something to do with how I'm calling process_article.

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