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”.

• Common Data Interface
• IAMC Data Interface
• Optimization Data Interface
• Pagination (ixmp4.data.pagination)