Avoid reinventing the wheels.
2015-07 But I still have one: gff2fa.py
GFF-Ex, a Genome Feature extraction package extracts Gene, Exon, Intron, Upstream Region of Gene (Promoters), Intergenic and CDS/cDNA sequences by just tweeting in the Genome Feature File (gff) along with the corresponding genome/chromosome sequence.
Question: Extract cds fastas from a gff annotation + reference sequence from biostars.org [bioperl needed]