networkx.algorithms.shortest_paths.astar.astar_path¶
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astar_path
(G, source, target, heuristic=None, weight='weight')[source]¶ Return a list of nodes in a shortest path between source and target using the A* (“A-star”) algorithm.
There may be more than one shortest path. This returns only one.
Parameters: - G (NetworkX graph)
- source (node) – Starting node for path
- target (node) – Ending node for path
- heuristic (function) – A function to evaluate the estimate of the distance from the a node to the target. The function takes two nodes arguments and must return a number.
- weight (string, optional (default=’weight’)) – Edge data key corresponding to the edge weight.
Raises: NetworkXNoPath
– If no path exists between source and target.Examples
>>> G = nx.path_graph(5) >>> print(nx.astar_path(G, 0, 4)) [0, 1, 2, 3, 4] >>> G = nx.grid_graph(dim=[3, 3]) # nodes are two-tuples (x,y) >>> nx.set_edge_attributes(G, {e: e[1][0]*2 for e in G.edges()}, 'cost') >>> def dist(a, b): ... (x1, y1) = a ... (x2, y2) = b ... return ((x1 - x2) ** 2 + (y1 - y2) ** 2) ** 0.5 >>> print(nx.astar_path(G, (0, 0), (2, 2), heuristic=dist, weight='cost')) [(0, 0), (0, 1), (0, 2), (1, 2), (2, 2)]
See also
shortest_path()
,dijkstra_path()