networkx.classes.function.is_negatively_weighted¶
-
is_negatively_weighted
(G, edge=None, weight='weight')[source]¶ Returns True if
G
has negatively weighted edges.- Parameters
G (graph) – A NetworkX graph.
edge (tuple, optional) – A 2-tuple specifying the only edge in
G
that will be tested. If None, then every edge inG
is tested.weight (string, optional) – The attribute name used to query for edge weights.
- Returns
A boolean signifying if
G
, or the specified edge, is negatively weighted.- Return type
- Raises
NetworkXError – If the specified edge does not exist.
Examples
>>> G = nx.Graph() >>> G.add_edges_from([(1, 3), (2, 4), (2, 6)]) >>> G.add_edge(1, 2, weight=4) >>> nx.is_negatively_weighted(G, (1, 2)) False >>> G[2][4]["weight"] = -2 >>> nx.is_negatively_weighted(G) True >>> G = nx.DiGraph() >>> edges = [("0", "3", 3), ("0", "1", -5), ("1", "0", -2)] >>> G.add_weighted_edges_from(edges) >>> nx.is_negatively_weighted(G) True