VPC w/ public subnet

vpc.py

#! /usr/bin/env python

from boto.vpc import VPCConnection
from boto.ec2 import get_region

EC2_REGION='ap-northeast-1'
VPC_CIDR='10.99.0.0/16'
PUBLIC_CIDR='10.99.0.0/24'


ec2region = get_region(EC2_REGION)
conn = VPCConnection(region=ec2region)

vpc = conn.create_vpc(VPC_CIDR)
igw = conn.create_internet_gateway()
conn.attach_internet_gateway(igw.id, vpc.id)

subnet = conn.create_subnet(vpc.id, PUBLIC_CIDR)

route_table = conn.get_all_route_tables(
    filters=[("vpc-id", vpc.id)])[0]
conn.create_route(route_table.id, '0.0.0.0/0', gateway_id=igw.id)

print "vpc-id %s created" % vpc.id