edgegraph.traversal.helpers.find_links

edgegraph.traversal.helpers.find_links(v1, v2, direction_sensitive=True, unknown_handling=2, filterfunc=None)

Find the link(s) that connect v1 to v2.

This function returns links that connect v1 and v2. If multiple links/edges connect the given vertices, they are all returned in a list. It respects edge directionality if/when necessary, and can handle arbitrary edge types given they are subclasses of either DirectedEdge or :py:class:~edgegraph.structure.undirectededge.UnDirectedEdge`.

For example, with the given graph:

the function would operate as:

>>> find_links(v1, v2)
{e1}
>>> find_links(v1, v4)
{e6}
>>> find_links(v1, v4, direction_sensitive=False)
{e6, e5}

If supplied, the filterfunc argument should be a callable object (function or otherwise) that will return either True or False. This function is used to determine if a given edge should be included in the returned set. It must have the following signature:

edgegraph.traversal.helpers.filterfunc(e)

Determines if a given edge (e) should be included in the returned set of edges between v1 and v2.

Parameters:

e – The edge under consideration.

Returns:

Whether or not e should be returned as part of the set of edges connecting v1 and v2.

Parameters:

• v1 (Vertex) – First vertex to find links from. In a directed edge, this is consiered the “from” vertex.

• v2 (Vertex) – Second vertex to find links from. In a directed edge, this is consiered the “to” vertex.

• direction_sensitive (bool) – Whether or not to respect edge directionality. If True (default), edges direcetd from v2 to v1 are ignored. If False, such edges are collected and returned.

• unknown_handling (int) –

  How to deal with classes that are subclasses of neither DirectedEdge nor UnDirectedEdge.

  • LNK_UNKNOWN_ERROR (default): Raise a NotImplementedError when such an edge is encountered.

  • LNK_UNKNOWN_NEIGHBOR: Skip unknown edges.

  • LNK_UNKNOWN_NONNEIGHBOR: Collect and return unknown edges.

• filterfunc (Callable | None) – Callable object that returns whether or not a given link should be included in the output.