Data Layer (ixmp4.data)

The ixmp4.data module organizes each datatype into a few files for consistency:

db.py: sqlalchemy database models and other database definitions
dto.py: a data transfer class for item serialization
exceptions.py: exceptions specific to the datatype (NotFound, NotUnique, etc.)
filter.py: filter definitions for use in repositories
repositories.py: repository classes responsible for interacting with the database
service.py: service class as the main interface for the datatype which combines all of the above

The service classes are instantiated together via a ixmp4.data.backend.Backend object which can be used by other code to perform operations in the database or on a remote ixmp4 http server. This construct and its classes can be referred to as the “data layer”.

Backend

class ixmp4.data.backend.IamcSubobject

Bases: object

Namespace grouping all IAMC-related data services on a Backend.

datapoints: DataPointService

timeseries: TimeSeriesService

variables: VariableService

regions: IamcRegionService

units: IamcUnitService

models: IamcModelService

scenarios: IamcScenarioService

class ixmp4.data.backend.OptimizationSubobject

Bases: object

Namespace grouping all optimization-related data services on a Backend.

equations: EquationService

indexsets: IndexSetService

parameters: ParameterService

scalars: ScalarService

tables: TableService

variables: VariableService

class ixmp4.data.backend.Backend(transport: Transport)

Bases: object

Central data-layer object that aggregates all service instances.

A Backend is built around a single Transport and exposes every data service as an attribute. IAMC-related services are grouped under iamc and optimisation-related services under optimization.

transport: Transport: The transport used by all services attached to this backend.

optimization: OptimizationSubobject: Namespace for optimisation services (equations, indexsets, parameters, …).

iamc: IamcSubobject: Namespace for IAMC data services (datapoints, timeseries, variables, …).

meta: RunMetaEntryService

models: ModelService

regions: RegionService

runs: RunService

scenarios: ScenarioService

units: UnitService

checkpoints: CheckpointService