"""
Module defining the `ImportExport` class that enables getting state variable
data in and out of groups in various formats (see `Group.get_states` and
`Group.set_states`).
"""
import abc
from abc import abstractmethod
[docs]
class ImportExport(metaclass=abc.ABCMeta):
"""
Class for registering new import/export methods (via static methods). Also
the base class that should be extended for such methods
(`ImportExport.export_data`, `ImportExport.import_data`, and
`ImportExport.name` have to be overwritten).
See Also
--------
VariableOwner.get_states, VariableOwner.set_states
"""
#: A dictionary mapping import/export methods names to `ImportExport` objects
methods = dict()
[docs]
@staticmethod
def register(importerexporter):
"""
Register a import/export method. Registered methods can be referred to
via their name.
Parameters
----------
importerexporter : `ImportExport`
The importerexporter object, e.g. an `DictImportExport`.
"""
if not isinstance(importerexporter, ImportExport):
t = str(type(importerexporter))
error_msg = (
f"Given importerexporter of type {t} does not seem to "
"be a valid importerexporter."
)
raise ValueError(error_msg)
name = importerexporter.name
if name in ImportExport.methods:
raise ValueError(
f"An import/export methods with the name '{name}'"
"has already been registered"
)
ImportExport.methods[name] = importerexporter
[docs]
@staticmethod
@abstractmethod
def export_data(group, variables):
"""
Asbtract static export data method with two obligatory parameters.
It should return a copy of the current state variable values. The
returned arrays are copies of the actual arrays that store the state
variable values, therefore changing the values in the returned
dictionary will not affect the state variables.
Parameters
----------
group : `Group`
Group object.
variables : list of str
The names of the variables to extract.
"""
raise NotImplementedError()
[docs]
@staticmethod
@abstractmethod
def import_data(group, data):
"""
Import and set state variables.
Parameters
----------
group : `Group`
Group object.
data : dict_like
Data to import with variable names.
"""
raise NotImplementedError()
@property
@abc.abstractmethod
def name(self):
"""
Abstract property giving a method name.
"""
pass