Removes duplicate sequence names from fasta file

removedup.py

#!/usr/bin/env python

import sys

from Bio import SeqIO

f = sys.argv[1]

seqs = SeqIO.parse(f,'fasta')

index = {}
for seq in seqs:
    if seq.id not in index:
        index[seq.id] = seq
with open('nodup.fasta','w') as fh:
    SeqIO.write(index.values(), fh, 'fasta')