Warning

This documents an unmaintained version of NetworkX. Please upgrade to a maintained version and see the current NetworkX documentation.

has_edge

Graph.has_edge(u, v)

Return True if the edge (u,v) is in the graph.

Parameters:v (u,) – Nodes can be, for example, strings or numbers. Nodes must be hashable (and not None) Python objects. Returns:edge_ind – True if edge is in the graph, False otherwise. Return type:bool

Examples

Can be called either using two nodes u,v or edge tuple (u,v)

>>> G = nx.Graph()   # or DiGraph, MultiGraph, MultiDiGraph, etc
>>> G.add_path([0,1,2,3])
>>> G.has_edge(0,1)  # using two nodes
True
>>> e = (0,1)
>>> G.has_edge(*e)  #  e is a 2-tuple (u,v)
True
>>> e = (0,1,{'weight':7})
>>> G.has_edge(*e[:2])  # e is a 3-tuple (u,v,data_dictionary)
True

The following syntax are all equivalent:

>>> G.has_edge(0,1)
True
>>> 1 in G[0]  # though this gives KeyError if 0 not in G
True