delete @hash{grep !/\d+_\d+/, keys %hash};

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Doesn't work in Perl versions before about 5.002, but should work in anything released in the last half dozen years.

-- Randal L. Schwartz, Perl hacker
Be sure to read my standard disclaimer if this is a reply.

In reply to •Re: Selecting particular key-value pairs in hashes by merlyn
in thread Selecting particular key-value pairs in hashes by kiat

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