dantro.utils.link module

Implements the Link class

class dantro.utils.link.Link(*, anchor: TGroupOrContainer, rel_path: str)

Bases: dantro.mixins.general.ForwardAttrsMixin

A link is a connection between two objects in the data tree, i.e. a data group and a data container.

It has a source object that it is coupled to and a relative path from that object to the target object.

Whenever attribute access occurs, an object of this class will resolve the linked object (if not already cached) and then forward the attribute call to that object.

FORWARD_ATTR_TO = 'target_object'

__init__(*, anchor: TGroupOrContainer, rel_path: str)

Initialize a link from an anchor and a relative path to a target

property target_weakref

Resolve the target and return the weak reference to it

property target_object

Return a (non-weak) reference to the actual target object

property anchor_weakref

Resolve the weak reference to the anchor and return it, i.e.: return a reference to the actual object.

property anchor_object

Return a (non-weak) reference to the anchor object

property target_rel_path

Returns the relative path to the target

_forward_attr_get_forwarding_target()

Get the object that the attribute call is to be forwarded to, i.e. the resolved target object. This invokes resolution of the target and caching of the corresponding weakref, but the returned (strong) ref will not be cached.

FORWARD_ATTR_EXCLUDE = ()

FORWARD_ATTR_ONLY = None

_Link__resolve_target_ref() → None

Resolves the weak reference to the target object and caches it

__getattr__(attr_name: str)

Forward attributes that were not available in this class to some other attribute of the group or container.

Parameters

attr_name (str) – The name of the attribute that was tried to be accessed but was not available in self.

Returns

The attribute attr_name of getattr(self, self.FORWARD_ATTR_TO)

_forward_attr_post_hook(attr)

Invoked before attribute forwarding occurs

_forward_attr_pre_hook(attr_name: str = None)

Invoked before attribute forwarding occurs