CODE EXAMPLE FOR PYTHON

double digest fasta files

import re,sys
from Bio import SeqIO

def print_ReSites(id,seqence):
    pattern=r"GATC"
    seq_len=len(seqence)
    sites = [str(m.start()) for m in re.finditer(pattern,seqence)]
    sites.append(str(seq_len))
    for start,end in zip(sites,sites[1:]):
        print id+"	"+start+"	"+end

for seq in SeqIO.parse(sys.argv[1],"fasta"):
    print_ReSites( str( seq.id),str(seq.seq))