#!/usr/bin/python
import re
for line in open('bushmen_chr7_all_snps.txt'):
line = line.rstrip()
columns = re.split('\t', line)
# columns[3] = reference; columns[5] = KB1
# columns[7] = NB1, columns[13] = ABT
# Find instances where both reference and
# ABT are different from KB1 and NB1
if columns[3] != 'N' and columns[5] != 'N' \
and columns[7] != 'N' and columns[13] != 'N' \
and columns[3] != columns[5] \
and columns[3] != columns[7] and columns[13] != columns[5] \
and columns[13] != columns[7]:
print line