使用 networkx 的最短路徑的邊緣屬性

Question

我正在嘗試使用 networkx 來計算兩個節點之間的最短路徑。 例如：

paths = nx.shortest_path(G, ‘A’, ‘C’, weight=‘cost’)

paths將返回類似於：['A', 'B', 'C']

nx.shortest_path_length()返回該路徑的成本，這也很有幫助。 但是，我還想返回為此路徑遍歷的邊列表。 在這些邊緣內是我存儲的其他屬性，我想返回。

這可能嗎？

Answer 1

這是一個可以滿足您所有需要的代碼（希望是：p）：

import numpy as np
# import matplotlib.pyplot as plt
import networkx as nx

# Create a random graph with 8 nodes, with degree=3
G = nx.random_regular_graph(3, 8, seed=None)

# Add 'cost' attributes to the edges
for (start, end) in G.edges:
    G.edges[start, end]['cost'] = np.random.randint(1,10)

# Find the shortest path from 0 to 7, use 'cost' as weight
sp = nx.shortest_path(G, source=0, target=7, weight='cost')
print("Shortest path: ", sp)

# Create a graph from 'sp'
pathGraph = nx.path_graph(sp)  # does not pass edges attributes

# Read attributes from each edge
for ea in pathGraph.edges():
    #print from_node, to_node, edge's attributes
    print(ea, G.edges[ea[0], ea[1]])

輸出將類似於以下內容：

Shortest path:  [0, 5, 7]
(0, 5) {'cost': 2}
(5, 7) {'cost': 3}

Answer 2

該腳本允許您獲取訪問邊緣的屬性列表

import networkx as nx
import matplotlib.pyplot as plt

Nodes = [('A', 'B'),('A', 'C'), ('C', 'D'), ('D', 'B'), ('C', 'B')]

G = nx.Graph()
num = 1 #name edge
for node in Nodes:
    G.add_edge(*node, num = num, weight = 1)
    num += 1

pos = nx.spring_layout(G)
edge_labels = nx.get_edge_attributes(G, 'num')
nx.draw(G,  with_labels=True, node_color='skyblue', pos=pos)
nx.draw_networkx_edge_labels(G, pos, edge_labels = edge_labels, font_color='red')
plt.show()

path = nx.shortest_path(G)
st = 'A' #start node
end = 'D' #end node
path_edges = [edge_labels.get(x, edge_labels.get((x[1],x[0]))) for x in zip(path[st][end], path[st][end][1:])]
print('Path by nodes: ', path[st][end])
print('Path by edges: ', path_edges)