AWS - Simple Lambda (python/boto3) function to stop EC2 instances

lambda_boto3_stop_ec2_instances.py

import boto3

def lambda_handler(event, context):
    
    # Get list of regions
    ec2_client = boto3.client('ec2')
    regions = [region['RegionName']
                for region in ec2_client.describe_regions()['Regions']]
                
    # Iterate over each region
    for region in regions:
        ec2 = boto3.resource('ec2', region_name=region)
    
        print("Region:", region)
        
        # Get all instances with status "running"
        instances = ec2.instances.filter(
            Filters=[{'Name': 'instance-state-name',
                        'Values': ['running']}])
                        
        # Stop running instances
        for instance in instances:
            instance.stop()
            print('Stopped instance: ', instance.id)