4.1.11.5. graph/Union¶

class mod.UnionGraph¶

An adaptor for a multiset of Graphs to present them as their disjoint union.

It functions as an iterable of the adapted graphs, and it implements the protocols.LabelledGraph protocol.

__init__()¶

__init__(graphs)

Construct a graph representing the disjoint union of graphs. Thus, if no graphs are given the empty graph is constructed.

Parameters: graphs (list[Graph]) – the list of graphs to adapt.

__str__()¶

Return type: str

__len__()¶

Returns: the number of adapted graphs.
Return type: int

__iter__()¶

Returns: the range of graphs adapted by this object.

__getitem__(i)¶

Returns: the ith adapted graph.
Return type: Graph
Raises: LogicError if i is out of range.

class Vertex¶

Implements the protocols.LabelledGraph.Vertex protocol. Additionally, the id is in the range \([0, numVertices[\).

A non-null vertex represents a specific Graph.Vertex. As the same Graph can be part of a UnionGraph multiple times, a vertex also has a graph index to determine which instance of a Graph in the UnionGraph the vertex refers to.

graphIndex¶

(Read-only) The index of the graph in the owning UnionGraph this vertex is from. The index is thus in the range \([0, len(graph)[\).

We can obtain the underlying Graph this vertex, self, is from both directly via the vertex attribute as self.vertex.graph, or via the graph index as self.graph[self.graphIndex].

Type: int
Raises: LogicError if it is a null vertex.

vertex¶

(Read-only) The underlying Graph.Vertex this vertex represents.

We can obtain the underlying Graph this vertex, self, is from both directly via the vertex attribute as self.vertex.graph, or via the graph index as self.graph[self.graphIndex].

Type: Graph.Vertex
Raises: LogicError if it is a null vertex.

class Edge¶

Implements the protocols.LabelledGraph.Vertex protocol.

A non-null edge represents a specific Graph.Edge. As the same Graph can be part of a UnionGraph multiple times, an edge also has a graph index to determine which instance of a Graph in the UnionGraph the edge refers to.

graphIndex¶

(Read-only) The index of the graph in the owning UnionGraph this edge is from. The index is thus in the range \([0, len(graph)[\).

We can obtain the underlying Graph this edge, self, is from both directly via the edge attribute as self.edge.graph, or via the graph index as self.graph[self.graphIndex].

Type: int
Raises: LogicError if it is a null edge.

edge¶

(Read-only) The underlying Graph.Edge this edge represents.

We can obtain the underlying Graph this edge, self, is from both directly via the edge attribute as self.edge.graph, or via the graph index as self.graph[self.graphIndex].

Type: Graph.Edge
Raises: LogicError if it is a null edge.

class VertexRange¶

Implements the protocols.Graph.VertexRange protocol, in addition to the following functionality.

__getitem__(i)¶

Returns: the ith vertex of the graph.
Return type: UnionGraph.Vertex

class EdgeRange¶: Implements the protocols.Graph.EdgeRange protocol.

class IncidentEdgeRange¶: Implements the protocols.Graph.IncidentEdgeRange protocol.

class mod.VertexMapUnionGraphUnionGraph¶: Implements the protocols.VertexMap protocol.