#

Note

This documents the development version of NetworkX. Documentation for the current release can be found here.

#

networkx.MultiGraph.has_edge

MultiGraph.has_edge(u, v, key=None)

Returns True if the graph has an edge between nodes u and v.

This is the same as v in G[u] or key in G[u][v] without KeyError exceptions.

Parameters

• u, v (nodes) – Nodes can be, for example, strings or numbers.

• key (hashable identifier, optional (default=None)) – If specified return True only if the edge with key is found.

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, an edge tuple (u, v), or an edge tuple (u, v, key).

>>> G = nx.MultiGraph()  # or MultiDiGraph
>>> nx.add_path(G, [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
>>> G.add_edge(0, 1, key="a")
'a'
>>> G.has_edge(0, 1, key="a")  # specify key
True
>>> e = (0, 1, "a")
>>> G.has_edge(*e)  # e is a 3-tuple (u, v, 'a')
True

The following syntax are equivalent:

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