Source code for fsc.hdf5_io._simple_mapping

Implements a base class for serializing a given list of attributes of an object.

import contextlib

from fsc.export import export

from ._base_classes import HDF5Enabled
from ._save_load import to_hdf5 as _global_to_hdf5, from_hdf5 as _global_from_hdf5

[docs]@export class SimpleHDF5Mapping(HDF5Enabled): """ Base class for data classes which simply map their member to HDF5 values / groups. The child class needs to define a list ``HDF5_ATTRIBUTES`` of attributes which should be serialized. The name of the attributes must correspond to the name accepted by the constructor. For attributes which *can* be serialized but are not required, it can also define a list ``HDF5_OPTIONAL``. The same logic as for the ``HDF5_ATTRIBUTES`` applies, but no error is raised if an attribute does not exist. """ HDF5_ATTRIBUTES = () HDF5_OPTIONAL = ()
[docs] @classmethod def from_hdf5(cls, hdf5_handle): cls._check_hdf5_attributes_lists() kwargs = dict() to_deserialize = list(cls.HDF5_ATTRIBUTES) + [ key for key in cls.HDF5_OPTIONAL if key in hdf5_handle ] for key in to_deserialize: hdf5_obj = hdf5_handle[key] try: kwargs[key] = hdf5_obj[()] except AttributeError: kwargs[key] = _global_from_hdf5(hdf5_obj) return cls(**kwargs)
[docs] def to_hdf5(self, hdf5_handle): self._check_hdf5_attributes_lists() to_serialize = [(key, getattr(self, key)) for key in self.HDF5_ATTRIBUTES] for key in self.HDF5_OPTIONAL: with contextlib.suppress(AttributeError): to_serialize.append((key, getattr(self, key))) for key, value in to_serialize: try: hdf5_handle[key] = value except TypeError: _global_to_hdf5(value, hdf5_handle.create_group(key))
@classmethod def _check_hdf5_attributes_lists(cls): """ Helper method to check that the HDF5_ATTRIBUTES and HDF5_OPTIONAL attributes of the class are consistent. """ for key in cls.HDF5_ATTRIBUTES: if not isinstance(key, str): raise ValueError( "The element '{key}' in {cls}.HDF5_ATTRIBUTES must be a string." .format(key=key, cls=cls) ) for key in cls.HDF5_OPTIONAL: if not isinstance(key, str): raise ValueError( "The element '{key}' in {cls}.HDF5_OPTIONAL must be a string." .format(key=key, cls=cls) ) overlapping_keys = set(cls.HDF5_ATTRIBUTES) & set(cls.HDF5_OPTIONAL) if overlapping_keys: raise ValueError( "The keys {overlapping_keys} are present in both {cls}.HDF5_ATTRIBUTES and {cls}.HDF5_OPTIONAL" .format(overlapping_keys=overlapping_keys, cls=cls) )