Graph

class ggsolver.graph.NodePropertyMap(graph, default=None)

Implements a default dictionary that maps a node ID to its property value. To store data efficiently, only the non-default values are stored in the dictionary.

Raises an error if the node ID is invalid.

__init__(graph, default=None)

class ggsolver.graph.EdgePropertyMap(graph, default=None)

Implements a default dictionary that maps an edge (uid, vid, key) to its property value. To store data efficiently, only the non-default values are stored in the dictionary.

Raises an error if the edge (uid, vid, key) is invalid.

__init__(graph, default=None)

class ggsolver.graph.Graph

A MultiDiGraph class represented as a 5-tuple (nodes, edges, node_properties, edge_properties, graph_properties). In addition, the graph implements a serialization protocol, save-load and drawing functionality.

__init__()

add_edge(uid, vid)

Adds a new edge between the give nodes.

Warning

Duplication is NOT checked. Hence, calling the function twice adds two parallel edges between the same nodes.

Returns

(int) Key of the added edge. Key = 0 means the first edge was added between the given nodes. If Key = k, then (k+1)-th edge was added.

add_edges(edges)

Adds multiple edge between the give nodes.

Warning

Duplication is NOT checked. Hence, calling the function twice adds two parallel edges between the same nodes.

Returns

(int) Key of the added edge. Key = 0 means the first edge was added between the given nodes. If Key = k, then (k+1)-th edge was added.

add_node()

Adds a new node to the graph.

Warning

Duplication is NOT checked.

Returns

(int) ID of the added node.

add_nodes(num_nodes)

Adds multiple nodes to the graph.

Warning

Duplication is NOT checked.

Parameters

num_nodes – (int) Number of nodes to be added.

Returns

(list) IDs of added nodes.

ancestors(uid)

List of all nodes from which the node represented by uid is reachable.

clear()

Clears all nodes, edges and the node, edge and graph properties.

descendants(uid)

List of all nodes that can be reached from the node represented by uid.

classmethod deserialize(obj_dict)

Constructs a graph from a serialized graph object. The format is described in Graph.serialize().

Returns

(Graph) A new Graph object..

property edge_properties

Returns the edge properties as a dictionary of {“property name”: EdgePropertyMap object}.

edges()

List of all edges in the graph. Each edge is represented as a 3-tuple (uid, vid, key).

property graph_properties

Returns the graph properties as a dictionary of {“property name”: property value}.

has_edge(uid, vid, key=None)

Checks whether the graph has the given edge or not.

Parameters

• uid – (int) Source node ID.

• vid – (int) Target node ID.

• key (int, optional) – If provided, checks whether the edge (u, v, k) is in the graph or not. Otherwise, checks if there exists an edge between nodes represented by uid and vid.

Returns

(bool) True if given edge is in the graph, else False.

has_node(uid)

Checks whether the graph has the given node or not.

Parameters

uid – (int) Node ID to be checked for containment.

Returns

(bool) True if given node is in the graph, else False.

in_edges(uid)

List of all in edges to the node represented by uid.

is_isomorphic_to(other: Graph)

Checks if the graph is isomorphic to the other graph.

Parameters

other – (Graph object) Graph to be checked for isomorphism with current graph.

Returns

(bool) True, if graphs are isomorphic. Else, False.

classmethod load(fpath, protocol='json')

Loads the graph from file.

Parameters

• fpath – (str) Path to which the file should be saved. Must include an extension.

• protocol – (str) The protocol to use to save the file. Options: {“json” [Default], “pickle”}.

Note

Pickle protocol is not tested.

neighbors(uid)

List of all (in and out) neighbors of the node represented by uid.

property node_properties

Returns the node properties as a dictionary of {“property name”: NodePropertyMap object}.

nodes()

List of all nodes in the graph.

number_of_edges()

The number of edges in the graph.

number_of_nodes()

The number of nodes in the graph.

out_edges(uid)

List of all out edges from the node represented by uid.

predecessors(uid)

List of all predecessors of the node represented by uid.

rem_edge(uid, vid, key)

Removal of edges is NOT supported. Use filtering instead.

rem_node(uid)

Removal of nodes is NOT supported. Use filtering instead.

save(fpath, overwrite=False, protocol='json')

Saves the graph to file.

Parameters

• fpath – (str) Path to which the file should be saved. Must include an extension.

• overwrite – (bool) Specifies whether to overwrite the file, if it exists. [Default: False]

• protocol – (str) The protocol to use to save the file. Options: {“json” [Default], “pickle”}.

Note

Pickle protocol is not tested.

serialize()

Serializes the graph into a dictionary with the following format:

{
    "graph": {
        "nodes": <number of nodes>,
        "edges": {
            uid: {vid: key},
            ...
        }
        "node_properties": {
            "property_name": {
                "default": <value>,
                "dict": {
                    "uid": <property value>,
                    ...
                }
            },
            ...
        },
        "edge_properties": {
            "property_name": {
                "default": <value>,
                "dict": [{"edge": [uid, vid, key], "pvalue": <property value>} ...]
            },
            ...
        },
        "graph_properties": {
            "property_name": <value>,
            ...
        }
    }
}

Returns

(dict) Serialized graph

successors(uid)

List of all successors of the node represented by uid.

to_png(fpath, nlabel=None, elabel=None)

Generates a PNG image of the graph.

Parameters

• fpath – (str) Path to which the file should be saved. Must include an extension.

• nlabel – (list of str) Specifies the node properties to use to annotate a node in image.

• elabel – (list of str) Specifies the edge properties to use to annotate an edge in image.

Warning

If the node labels are not unique, the generated figure may contain 0, 1, 2, … that avoid duplication.