MultiDiGraph.has_edge¶
- MultiDiGraph.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, vnodes
Nodes can be, for example, strings or numbers.
- keyhashable identifier, optional (default=None)
If specified return True only if the edge with key is found.
- Returns
- edge_indbool
True if edge is in the graph, False otherwise.
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