Parse an AWS ARN (Amazon Resource Name) into it's constituent elements

parse_arn.py

def parse_arn(arn):
    # http://docs.aws.amazon.com/general/latest/gr/aws-arns-and-namespaces.html
    elements = arn.split(':')
    result = {'arn': elements[0],
            'partition': elements[1],
            'service': elements[2],
            'region': elements[3],
            'account': elements[4]
           }
    if len(elements) == 7:
        result['resourcetype'], result['resource'] = elements[5:]
    elif '/' not in elements[5]:
        result['resource'] = elements[5]
        result['resourcetype'] = None
    else:
        result['resourcetype'], result['resource'] = elements[5].split('/')
    return result

This will parse at least rds auto snapshots' arns. they have ":" in the resource

I've created a similar library package for Go called awsarn, hope you don't mind too much if I leave a breadcrumb trail here :)

Fixed version to handle resource types and resources correctly.

def parse_arn(arn):
    # http://docs.aws.amazon.com/general/latest/gr/aws-arns-and-namespaces.html
    elements = arn.split(':', 5)
    result = {
        'arn': elements[0],
        'partition': elements[1],
        'service': elements[2],
        'region': elements[3],
        'account': elements[4],
        'resource': elements[5],
        'resource_type': None
    }
    if '/' in result['resource']:
        result['resource_type'], result['resource'] = result['resource'].split('/',1)
    elif ':' in result['resource']:
        result['resource_type'], result['resource'] = result['resource'].split(':',1)
    return result