Source code for saveable_objects.extensions._extensions

 1from typing import Optional, TypeVar, Generic
 2
 3from .. import SaveableObject
 4from .._meta_class import SaveAfterInitMetaClass
 5
 6T = TypeVar("T")
 7
 8class MetaSaveableWrapper(SaveAfterInitMetaClass):
 9    """A metaclass for the :class:`SaveableWrapper` class.`
10    """
11    def __call__(cls, class_to_wrap: Optional[type] = None, path: Optional[str] = None):
12        instance = type.__call__(cls, class_to_wrap, path)
13        if class_to_wrap is None:
14            return instance
15        else:
16            return instance[class_to_wrap]
17

[docs]
18class SaveableWrapper(Generic[T], SaveableObject, metaclass=MetaSaveableWrapper):
19    """A template class for converting a general class to a
20    :class:`SaveableObject <saveable_objects.SaveableObject>`. For example a
21    class ``T`` can be made into a new Saveable class ``SaveableT`` in any of
22    the following ways:
23
24    .. code-block:: python
25    
26        SaveableT = SaveableWrapper[T];
27        SaveableT = SaveableWrapper(T, path="default_path.pkl")
28        SaveableT = SaveableWrapper(path="default_path.pkl")[T];
29
30    A default path for the
31    :class:`SaveableObject <saveable_objects.SaveableObject>` can be set with
32    the ``path`` argument if parentheses are used.
33
34    The new class ``SaveableT`` will inherited from both ``T`` and
35    :class:`SaveableObject <saveable_objects.SaveableObject>`.
36    """
37    @staticmethod
38    def _get_class(arg: type, path_initialiser: Optional[str] = None):
39        class SaveableWrapped(arg, SaveableObject):
40            """Initialises the object of type ``T`` and next the
41            ``SaveableObject`` so that the initialisation of ``T`` is saved to
42            the file at ``path``.
43
44            Parameters
45            ----------
46            *args
47                The arguments to pass to the initialisation.
48            path : str, optional
49                File path to save the object to. If ``None`` then the object is
50                not saved. By default ``path_initialiser``
51            **kwargs
52                The keyword arguments to pass to the initialisation.
53            """
54            def __init__(self, *args, path: Optional[str] = path_initialiser, **kwargs):
55                arg.__init__(self, *args, **kwargs)
56                SaveableObject.__init__(self, path)
57        return SaveableWrapped
58    def __class_getitem__(cls, arg: type):
59        return cls._get_class(arg)
60    def __getitem__(self, arg: type):
61        return self._get_class(arg, self.default_path)
62    def __call__(self, arg: type):
63        return self._get_class(arg, self.default_path)
64    def __init__(self, class_to_wrap: Optional[type] = None, path: Optional[str] = None):
65        self.default_path = path
66        SaveableObject.__init__(self, None)