check security groups in a region if linked to a instance or not

sg-check.py

#!/usr/local/bin/python3
import re
from collections import OrderedDict
from pprint import pprint

import boto3

ec2 = None

# define your region and run in cloud shell
# python3 ./sg-check.py

ec2 = boto3.client('ec2', 'us-east-1')
linked = []
notlinked =[]
for sg in ec2.describe_security_groups()['SecurityGroups']:
    nw = ec2.describe_network_interfaces( Filters=[{'Name': 'group-id','Values': [sg['GroupId']]}]);
    nw = nw['NetworkInterfaces']
    if not nw :
        str = sg['GroupName']+' | '+sg['GroupId']+ ': Not Linked '
        notlinked.append(str);
    else:
        str = sg['GroupName']+' | '+sg['GroupId']+ ': Linked '
        linked.append(str)
print("===Linked===");
print("\n".join(linked));
print("===Not Linked===");
print("\n".join(notlinked));