col2tsv: converts a single column by breaking it up by the first column

col2tsv.py

#!/usr/bin/env python                                                                                         

import sys

n_rows = int(sys.argv[1])

data = map(lambda x: [], xrange(n_rows))
for k, line in enumerate(sys.stdin):
  data[k % n_rows] += [line.rstrip()]

for d in data:
  print "\t".join(d)