db.py

import gffutils
import sys
def parse_anotation(anotation_file):
    anotation = gffutils.create_db(dbfn=anotation_file, data="Somedata", force=True, keep_order=True, merge_strategy='merge', sort_attribute_values=True)
    db = gffutils.FeatureDB(anotation, keep_order=True)

    return db

def main(anotation_file):
    anotation = parse_anotation(anotation_file)
    for item in anotation.children(gene, featuretype="CDS"):
        print (item.start," ",item.end)

main(sys.argv[1])