aws pathon脚本定期删除snapshots

#!/usr/bin/env python3
import boto3
import time
from botocore.exceptions import ClientError

#take snapshots of long time once a week as delete  "cron(16 23 ? * 1 *)"

def delete_snapshot(snapshot_id):
    try:
        ec2resource = boto3.resource('ec2')
        snapshot = ec2resource.Snapshot(snapshot_id)
        snapshot.delete()
    except ClientError as e:
        print
        "Caught exception: %s" % e
    return

def lambda_handler(event, context):
    ec2 = boto3.client('ec2', region_name='ap-southeast-1')
    # Get all snapshots
    result = ec2.describe_snapshots(OwnerIds=['***************'])

    for snapshot in result['Snapshots']:
        if 'Tags' in snapshot:
            for tags in snapshot['Tags']:
                if tags["Key"] == "Date":
                    #Get the current timestamp
                    now = int(time.time())
                    snapshot_date = time.strptime(tags['Value'],"%Y%m%d-%H%M")
                    snapshot_date_stamp = int(time.mktime(snapshot_date))
                    # delete the snapshot if more than three months
                    if now - snapshot_date_stamp > 2592000*3:
                        #delete older snapshot
                        ec2.delete_snapshot(snapshot['SnapshotId'])
                        print("the snapshot of %s has been deleted." %(snapshot['SnapshotId']))
                    else:
                        print("this snapshot of %s is created for less than 3 months.." %(snapshot['SnapshotId']))


lambda_handler(2, 3)