一个必经点的最短路径

import matplotlib.pyplot as plt
import networkx as nx
gAnt=nx.Graph()
gAnt.add_weighted_edges_from([(0,1,3),(0,2,1),(0,3,1),
                            (1,2,1),(1,4,1),(1,9,4),
                            (2,3,1),(2,4,2),(2,5,1),
                            (3,5,2),(3,6,2),(3,7,1),
                            (4,5,1),(4,9,1),
                            (5,6,1),(5,9,3),(5,10,1),(5,12,3),
                            (6,7,1),(6,8,2),(6,12,2),(6,13,4),(6,14,3),
                            (7,8,1),
                            (8,14,1),(8,15,3),
                            (9,10,1),(9,11,1),
                            (10,11,1),(10,12,2),
                            (11,12,1),(11,16,1),
                            (12,13,2),(12,16,1),
                            (13,14,1),(13,15,2),(13,16,2),(13,17,1),
                            (14,15,1),
                            (15,17,4),
                            (16,17,1)])#向图中添加多条赋权边:(node1,node2,weight)
pos={0:(0,8),1:(7,12),2:(6,9),3:(5,6),4:(11,10),5:(14,8),#指定顶点位置
     6:(17,6),7:(10,4),8:(19,4),9:(18,12),10:(21,10),11:(28,12),
     12:(25,8),13:(30,7),14:(24,5),15:(29,4),16:(32,10),17:(37,8)}
minWPatha=nx.dijkstra_path(gAnt,source=0,target=6)#N0到N6的最短加权路径
lMinWPatha=nx.dijkstra_path_length(gAnt,source=0,target=6)#最短加权路径长度
minWPathb=nx.dijkstra_path(gAnt,source=6,target=17)# 6到N17的最短加权路径
lMinWPathb=nx.dijkstra_path_length(gAnt,source=6,target=17)#最短加权路径长度
minWPatha.extend(minWPathb[1:]) # 拼接 minWPath3a、minWPath3b 并去重 N7
print("\n问题: 一个必经点的约束")
print("S 到 E 的最短加权路径: ", minWPatha)
print("S 到 E 的最短加权路径长度: ", lMinWPath3a+lMinWPathb)
edgeList=[]
for i in range(len(minWPath3a)-1):
    edgeList.append((minWPath3a[i],minWPath3a[i+1]))
nx.draw_networkx_edges(gAnt,pos,edgelist=edgeList,edge_color='#ffc0cb',width=6)#设置边的颜色
nx.draw(gAnt,pos,with_labels=True,alpha=0.8)
labels=nx.get_edge_attributes(gAnt,'weight')
nx.draw_networkx_edge_labels(gAnt,pos,edge_labels=labels,font_color='c')#显示权值
nx.draw_networkx_nodes(gAnt,pos,nodelist=[0,17],node_color='yellow')#设置顶点颜色
nx.draw_networkx_nodes(gAnt,pos,nodelist=[7,12],node_color='lime')#设置顶点颜色
nx.draw_networkx_edges(gAnt,pos,edgelist=[(2,4),(13,14)],edge_color='lime',width=2.5)#设置边的颜色
nx.draw_networkx_edges(gAnt,pos,edgelist=[(11,12)],edge_color='r',width=2.5)#设置边的颜色
plt.show()