>>> import binascii
>>> binascii.unhexlify('9f')
'\x9f'
>>> hex(int('9f', 16))
'0x9f'
import binascii
with open('hexFile.txt') as f, open('test', 'wb') as fout:
for line in f:
fout.write(
binascii.unhexlify(''.join(line.split()))
)