Delete all layer versions in your account

delete_layers.py

import boto3

# if you use a separate profile for layers
session = boto3.Session(profile_name='LayerUploader')

regions = ['ap-northeast-1', 'ap-northeast-2', 'ap-south-1',
           'ap-southeast-1', 'ap-southeast-2', 'ca-central-1',
           'eu-central-1', 'eu-north-1', 'eu-west-1',
           'eu-west-2', 'eu-west-3', 'sa-east-1',
           'us-east-1', 'us-east-2','us-west-1',
           'us-west-2']

# Delete every version of every layer in every region
for region in regions:
    client = session.client('lambda', region_name=region)
    response = client.list_layers()
    for layer in response['Layers']:
        response = client.list_layer_versions(LayerName=layer['LayerName'])
        for version in response['LayerVersions']:
            print("{}:{}".format(layer['LayerName'], version['Version']))
            client.delete_layer_version(LayerName=layer['LayerName'],
                                        VersionNumber=version['Version'])