your code works pretty well on my machine. I used the next filecontent for a test:
input: 
CA 92037
CA 92021
CA 92055
CA 92037

[download]
delete: 
92037
92055

[download]
And this gave me the output: 
CA 92021

[download]
Maybe something wrong with your input-file format?

In reply to Re: A Problem With Hashes and Keys by eXile
in thread A Problem With Hashes and Keys by bivouac

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