pygraphs.graph_to_adjacency_list#

graph_to_adjacency_list(graph, *, weighted=False, weight_key='weight', dicted=True, skip_validation=False)[source]#

Convert a graph represented as a dictionary (GraphRepresentation) to a graph represented as an adjacency list (AdjacencyList).

  • AdjacencyList: List[List[Integral]]]: A list of lists, where the outer list has a length equal to the number of vertices in the graph, and each inner list contains the neighbors (i.e., [v1, v2, ...]) of the corresponding vertex (from outer vertex to inner vertex). For a weighted graph, the form List[List[Tuple[Integral, Real]]] is used where the inner lists contain tuples of the form \((v, w)\), where \(v\) is a neighbor vertex and \(w\) is the weight of the edge connecting the vertex to its neighbor. To store more than weight, the form List[List[Tuple[Integral, Dict[str, Any]]]] is used.

  • GraphRepresentation: Dict[int, Dict[int, Dict[str, Any]]]: A dictionary where the keys are vertex identifiers and the values are dictionaries mapping neighboring vertex identifiers to edge attributes (e.g., weight). This is the internal representation used by the pygraphs.Graph class.

Parameters:

  • graph (GraphRepresentation) – The graph represented as a dictionary.

  • weighted (bool, optional (default: False)) – Whether to represent the graph as List[List[Tuple[Integral, Real]]].

  • weight_key (Optional[str], optional (default: 'weight')) – The key to use for accessing the weight of an edge in the graph representation. Ignored if weighted is False.

  • dicted (bool, optional (default: False)) – Whether to represent the graph as List[List[Tuple[Integral, Dict[str, Any]]]].

Returns:

adjacency_list – The graph represented as an adjacency list.

Return type:

AdjacencyList