convert sanger output to fastq

sanger2fastq.py

#! /usr/bin/env python
import os
import sys

try:
    SEQ_DIR = sys.argv[1]
except:
    sys.stderr.write("Usage: python sanger2fastq.py <directory with.seq files>\n")
    sys.exit(1)

seq_files = os.listdir(SEQ_DIR)
#list comprehension (instead of for loop to modify items in list)
seq_files = [fname for fname in seq_files if ".seq" in fname]
fastq = open('mmp9_round2.fq', 'w')

for sf in seq_files:
    fname = os.path.join(SEQ_DIR, sf)
    f = open(fname, "r")
    read = ""
    lines = f.readlines()
    for l in lines:
        read = read + l.strip()
    f.close()
    read = read.replace(" ","")
    read_id = sf.strip(".seq")
    id = "@" + read_id
    read = read
    read_id = "+" + read_id
    qual = "D"*len(read)
    fastq.write(id + '\n')
    fastq.write(read + '\n')
    fastq.write(read_id + '\n')
    fastq.write(qual + '\n')
fastq.close()