Python script to stop all running instances in a region (AWS)

stop-instances.py

import boto3
ec2 = boto3.client('ec2')
response = ec2.describe_instances()
for reservation in response["Reservations"]:
    for instance in reservation["Instances"]:
        if instance["State"]["Name"] == "running":
            print("Stopping instance: " + instance["InstanceId"])
            ec2.stop_instances(InstanceIds=[instance["InstanceId"]])
            print("Instance stopped: " + instance["InstanceId"])
        else:    
            print("Instance is already stopped: " + instance["InstanceId"])
print("Script completed")