axt2one-line.py

#!/usr/bin/python3
#name: axt2one-line.py
import sys
import re
mydict = {}
args = sys.argv
reader = args[1]
writer = open(args[2],"w")
with open(reader) as fh:
    for line in fh:
        if re.search(r"\d+",line):
            header = line.strip()
            mydict[header] = []
        else:
            mydict[header].append(line.strip())
for key,value in mydict.items():
    seqs = "".join(value)
    length = len(seqs)
    mid = int(length/2)
    seq1 = seqs[0:mid]
    seq2 = seqs[mid:]
    writer.write(key + "\n" + "\n".join([seq1,seq2]))