dgl.DGLHeteroGraph.edge_id¶

DGLHeteroGraph.edge_id(u, v, force_multi=None, return_array=False, etype=None)[source]¶

Return the edge ID, or an array of edge IDs, between source node u and destination node v, with the specified edge type

Parameters:	u (int) – The node ID of source type. v (int) – The node ID of destination type. force_multi (bool, optional) – Deprecated (Will be deleted in the future). If False, will return a single edge ID. If True, will always return an array. (Default: False) return_array (bool, optional) – If False, will return a single edge ID. If True, will always return an array. (Default: False) etype (str or tuple of str, optional) – The edge type. Can be omitted if there is only one edge type in the graph.
Returns:	The edge ID if `return_array == False`. The edge ID array otherwise.
Return type:	int or tensor

Notes

If multiply edges exist between u and v and return_array is False, the result is undefined.

Examples

The following example uses PyTorch backend.

Instantiate a heterograph.

>>> plays_g = dgl.bipartite([(0, 0), (1, 0), (1, 2), (2, 1)], 'user', 'plays', 'game')
>>> follows_g = dgl.graph([(0, 1), (1, 2), (1, 2)], 'user', 'follows')
>>> g = dgl.hetero_from_relations([plays_g, follows_g])

Query for edge id.

>>> plays_g.edge_id(1, 2, etype=('user', 'plays', 'game'))
2
>>> g.edge_id(1, 2, return_array=True, etype=('user', 'follows', 'user'))
tensor([1, 2])