ScheduleStopInstance.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 only running instances
        instances = ec2.instances.filter(
            Filters=[{'Name': 'instance-state-name', 'Values':['running']}])
            
        #Stop the instances
        for instance in instances:
            instance.stop()
            print('Stopped instance', instance.id)