def production_variant(model_name, instance_type, initial_instance_count=1,
    variant_name='AllTraffic', initial_weight=1, accelerator_type=None):
    """Create a production variant description suitable for use in a ``ProductionVariant`` list as
    part of a ``CreateEndpointConfig`` request.

    Args:
        model_name (str): The name of the SageMaker model this production variant references.
        instance_type (str): The EC2 instance type for this production variant. For example,
            'ml.c4.8xlarge'.
        initial_instance_count (int): The initial instance count for this production variant
            (default: 1).
        variant_name (string): The ``VariantName`` of this production variant
            (default: 'AllTraffic').
        initial_weight (int): The relative ``InitialVariantWeight`` of this production variant
            (default: 1).
        accelerator_type (str): Type of Elastic Inference accelerator for this production variant.
            For example, 'ml.eia1.medium'.
            For more information: https://docs.aws.amazon.com/sagemaker/latest/dg/ei.html

    Returns:
        dict[str, str]: An SageMaker ``ProductionVariant`` description
    """
    production_variant_configuration = {'ModelName': model_name,
        'InstanceType': instance_type, 'InitialInstanceCount':
        initial_instance_count, 'VariantName': variant_name,
        'InitialVariantWeight': initial_weight}
    if accelerator_type:
        production_variant_configuration['AcceleratorType'] = accelerator_type
    return production_variant_configuration
