"""Settings that are indirectly related to experiments."""
from __future__ import annotations
from qcodes.dataset.sqlite.connection import ConnectionPlus, path_to_dbfile
from qcodes.dataset.sqlite.queries import get_last_experiment
_default_experiment: dict[str, int | None] = {}
def _set_default_experiment_id(db_path: str, exp_id: int) -> None:
"""
Sets the default experiment with the exp_id of a created/ loaded
experiment for the database that this experiment belongs to.
Args:
db_path: The database that a created/ loaded experiment belongs to.
exp_id: The exp_id of a created/ loaded experiment.
"""
global _default_experiment
_default_experiment[db_path] = exp_id
def _get_latest_default_experiment_id(db_path: str) -> int | None:
"""
Gets the latest created or loaded experiment's exp_id. If no experiment is set
None will be returned.
Args:
db_path: Database path.
Returns:
The latest created/ loaded experiment's exp_id.
"""
global _default_experiment
return _default_experiment.get(db_path, None)
[docs]
def reset_default_experiment_id(conn: ConnectionPlus | None = None) -> None:
"""
Resets the default experiment id to to the last experiment in the db.
"""
global _default_experiment
if conn is None:
_default_experiment = {}
else:
db_path = path_to_dbfile(conn)
_default_experiment[db_path] = None
[docs]
def get_default_experiment_id(conn: ConnectionPlus) -> int:
"""
Returns the latest created/ loaded experiment's exp_id as the default
experiment. If it is not set the maximum exp_id returned as the default.
If no experiment is found in the database, a ValueError is raised.
Args:
conn: Open connection to the db in question.
Returns:
exp_id of the default experiment.
Raises:
ValueError: If no experiment exists in the given db.
"""
db_path = path_to_dbfile(conn)
exp_id = _get_latest_default_experiment_id(db_path)
if exp_id is None:
exp_id = get_last_experiment(conn)
if exp_id is None:
raise ValueError(
"No experiments found."
" You can create one with:"
" new_experiment(name, sample_name)"
)
return exp_id