Functions

Functional interface to graph methods and assorted utilities.

Graph

degree(G[, nbunch, weight])	Returns a degree view of single node or of nbunch of nodes.
degree_histogram(G)	Returns a list of the frequency of each degree value.
density(G)	Returns the density of a graph.
create_empty_copy(G[, with_data])	Returns a copy of the graph G with all of the edges removed.
is_directed(G)	Return True if graph is directed.
to_directed(graph)	Returns a directed view of the graph graph.
to_undirected(graph)	Returns an undirected view of the graph graph.
is_empty(G)	Returns True if G has no edges.
add_star(G_to_add_to, nodes_for_star, **attr)	Add a star to Graph G_to_add_to.
add_path(G_to_add_to, nodes_for_path, **attr)	Add a path to the Graph G_to_add_to.
add_cycle(G_to_add_to, nodes_for_cycle, **attr)	Add a cycle to the Graph G_to_add_to.
subgraph(G, nbunch)	Returns the subgraph induced on nodes in nbunch.
induced_subgraph(G, nbunch)	Returns a SubGraph view of G showing only nodes in nbunch.
restricted_view(G, nodes, edges)	Returns a view of G with hidden nodes and edges.
edge_subgraph(G, edges)	Returns a view of the subgraph induced by the specified edges.

Nodes

nodes(G)	Returns a NodeView over the graph nodes.
number_of_nodes(G)	Returns the number of nodes in the graph.
neighbors(G, n)	Returns an iterator over all neighbors of node n.
all_neighbors(graph, node)	Returns all of the neighbors of a node in the graph.
non_neighbors(graph, node)	Returns the non-neighbors of the node in the graph.
common_neighbors(G, u, v)	Returns the common neighbors of two nodes in a graph.

Edges

edges(G[, nbunch])	Returns an edge view of edges incident to nodes in nbunch.
number_of_edges(G)	Returns the number of edges in the graph.
density(G)	Returns the density of a graph.
non_edges(graph)	Returns the nonexistent edges in the graph.

Self loops

selfloop_edges(G[, data, keys, default])	Returns an iterator over selfloop edges.
number_of_selfloops(G)	Returns the number of selfloop edges.
nodes_with_selfloops(G)	Returns an iterator over nodes with self loops.

Attributes

is_weighted(G[, edge, weight])	Returns True if G has weighted edges.
is_negatively_weighted(G[, edge, weight])	Returns True if G has negatively weighted edges.
set_node_attributes(G, values[, name])	Sets node attributes from a given value or dictionary of values.
get_node_attributes(G, name[, default])	Get node attributes from graph
set_edge_attributes(G, values[, name])	Sets edge attributes from a given value or dictionary of values.
get_edge_attributes(G, name[, default])	Get edge attributes from graph

Paths

is_path(G, path)	Returns whether or not the specified path exists.
path_weight(G, path, weight)	Returns total cost associated with specified path and weight

Freezing graph structure

freeze(G)	Modify graph to prevent further change by adding or removing nodes or edges.
is_frozen(G)	Returns True if graph is frozen.