edgegraph.structure.vertex.Vertex

class edgegraph.structure.vertex.Vertex(*, links=None, uid=None, attributes=None, universes=None)

Bases: BaseObject

Represents a vertex in an edge-vertex graph.

This class is a base class for anything that needs to “relate to” something else – another instance, or completely different types (as long as they both subclass this one, at some level).

__init__(*, links=None, uid=None, attributes=None, universes=None)

Creates a new vertex.

Unlike BaseObject, the Vertex class will add itself to Universes provided to this method.

Parameters:

links (list[Link]) – iterable of link objects to associate this vertex with

See also

• edgegraph.structure.base.BaseObject.__init__(), the superclass constructor

Methods

__init__(*[, links, uid, attributes, universes])	Creates a new vertex.
add_to_link(link)	Add this vertex to a link.
add_to_universe(universe)	Adds this object to a new universe.
remove_from_link(link)	Remove this vertex from a link.
remove_from_universe(universe)	Remove this object from the specified universe.

Attributes

links	Return a tuple of links that are attached to this object.
uid	Get the UID of this object.
universes	Get the universes this object belongs to.

add_to_link(link)

Add this vertex to a link.

Roughly equivalent to calling the Link’s add_vertex() with this object as an argument.

If the given link is already associated with this vertex, no action is taken.

Attention

Duplicate links ARE allowed! However, the same link twice is not. The difference is that of a == vs is comparison. == duplicate links are allowed, is duplicate links are ignored.

Parameters:

link (Link) – the link to add this vertex to

add_to_universe(universe)

Adds this object to a new universe. If it is already there, no action is taken.

In addition to the action(s) taken by the superclass (add_to_universe()), this method also adds this vertex to the universes’ reference of vertices, if needed.

Parameters:

universe (Universe) – the new universe to add this object to

property links: tuple[Link]

Return a tuple of links that are attached to this object.

A tuple is given specifically to prevent the addition or removal of link objects using this attribute; it is intended to be immutable.

remove_from_link(link)

Remove this vertex from a link.

Parameters:

link (Link) – the link to remove this vertex from.

remove_from_universe(universe)

Remove this object from the specified universe.

Parameters:

universe (Universe) – the universe that this object will be removed from

Raises:

KeyError – if this object is not present in the given universe

property uid: int

Get the UID of this object.

property universes: frozenset[Universe]

Get the universes this object belongs to.

Note that this gives you a frozenset; you cannot add or remove universes from this attribute.

See also

add_to_universe(), remove_from_universe() to add or remove this object from a given universe

Return type:

frozenset[Universe]