What strategy for random accession of records in massive FASTA file?

[Chris Lasher]

Roy, thank you for your reply. I have BioPython installed on my box at
work and have been browsing through the code in there, some of which I
can follow, and most of which will take more time and experience for me
to do so. I have considered BioPython and databases, and have chosen to
forego those routes for the reasons above, here summarized: this script
has a limited scope of what I hope it will acheive, and it should be as
convenient as possible for the end-user to execute it (even at the
expense of convenience to me as the coder). Again, thanks for your
input, though. It's very helpful to me to be able to learn from other
perspectives that I wouldn't have seen from, myself.