如何获取两个节点之间最小路径的权重？

Question

我在 Python 中有一个带有加权边的 networkx 图。我想获取两个节点之间最小路径的权值。

目前，我正在从 nx.shortest_path 实现中获取最短路径中的节点，然后遍历每一对并对每对节点之间的权重求和。

shortest_path = nx.shortest_path(G, source, destination, 'distance')

#function to iterate over each pair

import itertools
def pairwise(iterable):
    a, b = itertools.tee(iterable)
    next(b, None)
    return zip(a, b)

weightSum = 0
for adjPair in pairwise(shortest_path):
    weightSum = weightSum + G[adjPair[0]][adjPair[1]]['distance']

是否有更好的（内置）替代方案？

Answer 1

networkx 文档有此页面：shortest paths。

有几个选项，但看起来 shortest_path_length() 是您想要的。

为清楚起见：

shortest_path = nx.shortest_path_length(G, source, destination, 'distance')

Answer 2

你找single_source_dijkstra:

from networkx.algorithms.shortest_paths.weighted import single_source_dijkstra

single_source_dijkstra(G,s,t)

例子

import networkx as nx
from networkx.algorithms.shortest_paths.weighted import single_source_dijkstra

G = nx.Graph()

G.add_edge('a', 'b', weight=0.6)
G.add_edge('a', 'c', weight=6)
G.add_edge('c', 'd', weight=0.1)
G.add_edge('c', 'e', weight=0.7)
G.add_edge('c', 'f', weight=0.9)
G.add_edge('a', 'd', weight=0.3)

single_source_dijkstra(G,'b','f')

输出

(1.9, ['b', 'a', 'd', 'c', 'f'])

如何获取两个节点之间最小路径的权重？

How to get the weight of the smallest path between two nodes?

python

python-3.x

networkx

shortest-path

dijkstra