#!/usr/bin/env python3

'''
    filter out illegal sequence that contain words except ATCG,
    filter out short sequence(<200 bp),
    and output one line format fasta.
'''

import sys
from bio.seq.base import Fasta, write_fasta_o

infile = sys.argv[1]
outfile = sys.stdout
for seq in Fasta(infile,l_lowlim=200):
    if seq.isnucleotide():
        write_fasta_o(outfile,seq,lth=0)