I have needed this for a while but I would have thought someone would have done this by now, yet I have never seen any code that does this. Get the latest AMI. -- In this case we are hard coding everything but, merely change the `parse` and `filters` phrases, and you can grep for the latest on what you want.

get_latest_ami.py

#!/usr/bin/env python

import boto
import sys
from parse import *
import datetime 

ec2 = boto.connect_ec2(debug=0)
image_meta = ec2.get_all_images(filters={'name': 'amzn-ami-hvm-*gp2'})

date_list = []
number_images = 0
while number_images != len(image_meta):
        image_name = parse('amzn-ami-hvm-{}.x86_64-gp2',
            image_meta[number_images].name)[0]
        date_list.append(image_name)
        latest_image = sorted(date_list, reverse=True)[0]
        number_images += 1
        if latest_image == image_name:
            image = image_meta[number_images].id

print image