Unused AWS Security Group cleanup

cleanup.py

#!/usr/bin/env python3
import boto3

dryrun = True

regions = boto3.client('ec2').describe_regions()['Regions']

for region in regions:
  print('\n\n{}\n\n'.format(region['RegionName']))
  ec2 = boto3.client('ec2', region_name=region['RegionName'])
  sgs_paginator = ec2.get_paginator('describe_security_groups')
  for sgs in sgs_paginator.paginate():
    for sg in sgs['SecurityGroups']:
      sg_id = sg['GroupId']
      resp = ec2.describe_network_interfaces(Filters=[{'Name':'group-id', 'Values':[sg_id]}])
      if len(resp['NetworkInterfaces']) == 0:
        print('{} {} {}'.format(sg.get('VpcId', ' ' * 12), sg_id, sg['GroupName']))
        if not dryrun:
          ec2.delete_security_group(GroupId=sg_id)