#!/usr/bin/env python
from __future__ import print_function
import boto3

def get_instances(r):
    return r['Instances']

def private_ip(i):
    if i[0].has_key('PrivateIpAddress'):
        return i[0]['PrivateIpAddress']

def get_private_ips(instanceLookup):
    return map(private_ip, map(get_instances, instanceLookup['Reservations']))
    
print(*get_private_ips(boto3.Session().client('ec2').describe_instances()), sep='\n')