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Reading input files with GemsPy

GemsPy supports two loading strategies: a directory-based approach that reads an entire study at once, and a file-by-file approach for programmatic control.

When your study follows the standard directory layout, use load_study():

my_study/
├── input/
│   ├── system.yml
│   ├── optim-config.yml
│   ├── model-libraries/
│   │   └── *.yml
│   └── data-series/
│       ├── modeler-scenariobuilder.dat   ← optional
│       └── *.txt / *.csv

from pathlib import Path
from gems_craft.study.folder import load_study

study = load_study(Path("my_study"))

load_study() returns a Study object that bundles the resolved System, the DataBase with all parameter values, and the ScenarioBuilder loaded from input/data-series/modeler-scenariobuilder.dat (if present).

File-by-file loading (programmatic)

Use the lower-level functions when you want to load files individually or build parts of the study from in-memory data.

Loading the library and the system

from gems_craft.model.parsing import parse_yaml_library
from gems_craft.model.resolve_library import resolve_library
from gems_craft.study.parsing import parse_yaml_system
from gems_craft.study.resolve_components import resolve_system, build_data_base
from pathlib import Path

with open("simple_library.yml") as lib_file:
    input_libraries = [parse_yaml_library(lib_file)]

with open("system_example.yml") as compo_file:
    input_system = parse_yaml_system(compo_file)

result_lib = resolve_library(input_libraries)
system = resolve_system(input_system, result_lib)

Loading timeseries data

database = build_data_base(input_system, Path(series_dir))

build_data_base() reads all timeseries files referenced by the system (.txt or .csv) from series_dir.

Assembling a Study

Once you have system and database, wrap them in a Study:

from gems_craft.study import Study

study = Study(system=system, database=database)

This study object can then be passed directly to build_problem() or SimulationSession.

Hybrid studies (gems_craft_hybrid)

Hybrid GEMS studies extend the standard format with additional fields used to interoperate with Antares Simulator.

Limitation: hybrid studies cannot be simulated with GemsPy. The gems_craft_hybrid package only provides reading and writing of hybrid files.

Hybrid libraries and hybrid systems

For the YAML fields in library and system files associated with the hybrid mode, see this page of the GEMS documentation website.

Load and write hybrid libraries with parse_yaml_hybrid_library / write_yaml_library:

from gems_craft.model.parsing import write_yaml_library
from gems_craft_hybrid.model.parsing import parse_yaml_hybrid_library

with open("hybrid_lib.yml") as f:
    library = parse_yaml_hybrid_library(f)
write_yaml_library(library, Path("output/hybrid_lib.yml"))

Load and write hybrid systems with parse_yaml_hybrid_system / write_yaml_system:

from gems_craft.study.parsing import write_yaml_system
from gems_craft_hybrid.study.parsing import parse_yaml_hybrid_system

with open("hybrid_system.yml") as f:
    system = parse_yaml_hybrid_system(f)
write_yaml_system(system, Path("output/hybrid_system.yml"))