pyrdf2vec.samplers.sampler module¶

class pyrdf2vec.samplers.sampler.Sampler(inverse=False, split=False)¶

Base class of the sampling strategies.

_is_support_remote¶: True if the sampling strategy can be used with a remote Knowledge Graph, False Otherwise Defaults to False.

_random_state¶: The random state to use to keep random determinism with the sampling strategy. Defaults to None.

_visited¶: Tags vertices that appear at the max depth or of which all their children are tagged. Defaults to set.

inverse¶: True if the inverse algorithm must be used, False otherwise. Defaults to False.

split¶: True if the split algorithm must be used, False otherwise. Defaults to False.

abstract fit(kg)¶

Fits the sampling strategy.

Parameters: kg (KG) – The Knowledge Graph.
Raises: SamplerNotSupported – If there is an attempt to use an invalid sampling strategy to a remote Knowledge Graph.
Return type: None

abstract get_weight(hop)¶

Gets the weight of a hop in the Knowledge Graph.

Parameters: hop (Tuple[Any, Any]) – The hop of a vertex in a (predicate, object) form to get the weight.
Returns: The weight of a given hop.
Raises: NotImplementedError – If this method is called, without having provided an implementation.

get_weights(hops)¶

Gets the weights of the provided hops.

Parameters: hops (List[Tuple[Any, Any]]) – The hops to get the weights.
Return type: Optional[List[float]]
Returns: The weights to the edge of the Knowledge Graph.

property random_state: Optional[int]¶

Gets the random state.

sample_hop(kg, walk, is_last_hop, is_reverse=False)¶

Samples an unvisited random hop in the (predicate, object) form, according to the weight of hops for a given walk.

Parameters

kg (KG) – The Knowledge Graph.
walk (Tuple[Any, ...]) – The walk with one or several vertices.
is_last_hop (bool) – True if the next hop to be visited is the last one for the desired depth, False otherwise.
is_reverse (bool) – True to get the parent neighbors instead of the child neighbors, False otherwise. Defaults to False.

Return type

Optional[Tuple[Any, Any]]

Returns

An unvisited hop in the (predicate, object) form.

property visited: Set[Tuple[Tuple[Any, Any], int]]¶

Gets the tagged vertices that appear at the max depth or of which all their children are tagged.

exception pyrdf2vec.samplers.sampler.SamplerNotSupported¶

Base exception class for the lack of support of a sampling strategy for the extraction of walks via a SPARQL endpoint server.