outputs keypairs registered in region and what's in use for ec2 instances

pem.py

import boto3
regions = ['us-east-1', 'us-east-2', 'us-west-1', 'us-west-2']

def get_hostname(instance):
     if instance.tags:
          for tag in instance.tags:
               if tag["Key"] == 'Name':
                    return tag["Value"]
     return "Unknown"

def get_keys_in_use(regions):
     print("Getting keys in use by instances")
     keys_with_regions = {}

     for region in regions:
          key_names = set()
          
          ec2 = boto3.resource('ec2', region_name=region)
          instances = ec2.instances.filter(
               Filters=[{'Name': 'instance-state-name', 'Values': ['running', 'stopped']}])

          for instance in instances:
               hostname = get_hostname(instance)
               if instance.key_name:
                    key_names.add(instance.key_name)

               print(f"Region: {region} InstanceId: {instance.id} Key: {instance.key_name} Name: {hostname} State: {instance.state['Name']}")

          keys_with_regions[region] = list(key_names)
     
     print(keys_with_regions)

def get_keys_for_regions(regions):
     print("Gettings keys registered in AWS Region")
     keys_with_regions = {}

     for region in regions:
          key_names = []
          print(f'Checking {region}')
          ec2 = boto3.client('ec2', region_name=region)
          response = ec2.describe_key_pairs()

          for key in response['KeyPairs']:
               #Add key name to list
               key_names.append(key['KeyName'])
          
          #Add keys for region to master dictionary
          keys_with_regions[region] = key_names

     #All Keys across regions
     print(keys_with_regions)


get_keys_in_use(regions)
get_keys_for_regions(regions)