http://undertitled.com/2012/04/11/bookkeeping-with-libcloud.html

bookkeeping.py

#!/usr/bin/env python

import locale
from libcloud.compute.types import Provider
from libcloud.compute.providers import get_driver

RACKSPACE_USER = 'YOUR_USERNAME_HERE'
RACKSPACE_KEY = 'YOUR_API_KEY_HERE'
HOURS_PER_MONTH = 730.484 # according to magical google calculator
DELIMITER = '\t'

# helper to convert items in list to str, and join with DELIMITER
def assemble_line(words):
    return DELIMITER.join([str(word) for word in words])

def format_price(price):
    # for US-style dollar amounts
    locale.setlocale(locale.LC_ALL, 'en_US')
    return '${}'.format(locale.format('%0.2f', price, grouping=True))

def main():
    Driver = get_driver(Provider.RACKSPACE)
    conn = Driver(RACKSPACE_USER, RACKSPACE_KEY)

    nodes = conn.list_nodes()
    sizes = conn.list_sizes()

    nodes_by_size = {}
    summary = []
    output = []

    # sort nodes by name
    nodes.sort(lambda x, y: cmp(x.name, y.name))

    for node in nodes:
        size = [s for s in sizes if s.id == node.extra['flavorId']][0]
        size_name = str(size.ram)

        if size in nodes_by_size:
            nodes_by_size[size].append(node)
        else:
            nodes_by_size[size] = [node]

        month_price = size.price * HOURS_PER_MONTH
        output.append((node.name, size_name, format_price(month_price)))

    # calculate total monthly price, broken down by size
    for size, nodes in nodes_by_size.iteritems():
        num_nodes = len(nodes)
        month_price = size.price * HOURS_PER_MONTH
        nodes_total_price = month_price * num_nodes

        summary.append((size.ram,                         # size
                        num_nodes,                        # number of nodes
                        format_price(month_price),        # price per node per month
                        format_price(nodes_total_price))) # total price per month

    total_num_nodes = sum(len(nodes) for nodes in nodes_by_size.values())
    total_price = sum(size.price * HOURS_PER_MONTH * len(nodes)
                      for size, nodes
                      in nodes_by_size.iteritems())

    summary.append(('',
                    total_num_nodes,
                    '',
                    format_price(total_price)))

    # output
    print('Summary')
    print(assemble_line(('Size',
                         'Nodes',
                         '$/Nodes/Month',
                         '$/Month')))
    print('\n'.join([assemble_line(line) for line in summary]))
    print
    print('Inventory')
    print('\n'.join([assemble_line(line) for line in output]))

if __name__ == '__main__':
    main()