For that time that someone leaves unused EC2 and FSx running in a bunch of sub-accounts in an AWS Organization. Supply the list of subaccounts to assume-role into.

nuke_ec2_fsx.py

#!/usr/bin/env python

from __future__ import print_function
import boto3
import botocore
import time
import sys
import argparse
import pandas

def clean_account(
        account_id, region
        ):

    sts_client = boto3.client('sts')
    
    # Call the assume_role method of the STSConnection object and pass the role
    # ARN and a role session name.
    assumed_role_object=sts_client.assume_role(
            RoleArn=f"arn:aws:iam::{account_id:012d}:role/OrganizationAccountAccessRole",
        RoleSessionName="AssumeRoleSession1"
    )
    
    # From the response that contains the assumed role, get the temporary 
    # credentials that can be used to make subsequent API calls
    credentials=assumed_role_object['Credentials']
    ec2_client = boto3.client('ec2', aws_access_key_id=credentials['AccessKeyId'], aws_secret_access_key=credentials['SecretAccessKey'], aws_session_token=credentials['SessionToken'], region_name=region)
    ec2_instances = ec2_client.describe_instances()
    ec2_reservations = ec2_instances['Reservations']
    for reservation in ec2_reservations:
        ec2_instances = reservation['Instances']
        instanceIds = []
        for instance in ec2_instances:
            print(f"EC2: Region: {region} ID: {instance['InstanceId']} Type: {instance['InstanceType']} LaunchType: {instance['LaunchTime']} State: {instance['State']['Name']}")
            instanceIds.append(instance['InstanceId'])
        ec2_client.terminate_instances(InstanceIds=instanceIds)
    
    fsx_client = boto3.client('fsx', aws_access_key_id=credentials['AccessKeyId'], aws_secret_access_key=credentials['SecretAccessKey'], aws_session_token=credentials['SessionToken'], region_name=region)
    
    filesystems = fsx_client.describe_file_systems()
    for fs in filesystems['FileSystems']:
        print(f"Region: {region} Filesystem: {fs['FileSystemId']} ")
        response = fsx_client.delete_file_system(FileSystemId=fs['FileSystemId'], WindowsConfiguration={'SkipFinalBackup': True})

    iam_client = boto3.client('iam', aws_access_key_id=credentials['AccessKeyId'], aws_secret_access_key=credentials['SecretAccessKey'], aws_session_token=credentials['SessionToken'])
    roles = iam_client.list_roles()
    for role in roles['Roles']:
        if role['RoleName'].startswith('fsx'):
            print(f"Deleting role {role['RoleName']}")
            instance_profiles = iam_client.list_instance_profiles_for_role(RoleName=role['RoleName'])
            for ip in instance_profiles['InstanceProfiles']:
                iam_client.remove_role_from_instance_profile(RoleName=role['RoleName'],InstanceProfileName=ip['InstanceProfileName'])

            iam_client.delete_role(RoleName=role['RoleName'])

    ds_client = boto3.client('ds', aws_access_key_id=credentials['AccessKeyId'], aws_secret_access_key=credentials['SecretAccessKey'], aws_session_token=credentials['SessionToken'], region_name=region)
    directories = ds_client.describe_directories()
    for ds in directories['DirectoryDescriptions']:
        print(f"Deleting directory {ds['DirectoryId']} {ds['Name']}")
        ds_client.delete_directory(DirectoryId=ds['DirectoryId'])

def main(arguments):

    accounts = pandas.read_csv('accounts.csv')
    
    for account in accounts.AccountId:
        print(f"AWS Account: {account:012d}")
        clean_account(account, "us-east-1")
        clean_account(account, "us-east-2")
        clean_account(account, "us-west-1")
        clean_account(account, "us-west-2")
        clean_account(account, "ap-southeast-2")
        print("")


if __name__ == '__main__':
    sys.exit(main(sys.argv[1:]))