上述代码报错：AttributeError: 'tuple' object has no attribute 'items'

抱歉，我的错误。`nx.all_pairs_dijkstra` 返回的是一个生成器对象，每个元素是一个二元组，表示一个起始节点到其他节点的最短路径和路径长度。因此，需要对生成器对象进行循环遍历，然后再对每个二元组中的第二个元素进行遍历获取每个节点和其对应的最短路径长度。以下是修改后的代码：

import pandas as pd
import numpy as np
import networkx as nx
import matplotlib.pyplot as plt

df = pd.read_excel(r"C:\Users\li'yi'jie\Desktop\运筹学网络规划数据.xlsx")
edges = []
for i in range(len(df)):
    edge = {
        "id": df.loc[i, "边的编号"],
        "tail": df.loc[i, "边的尾节点"],
        "head": df.loc[i, "边的头节点"],
        "length": df.loc[i, "长度"],
        "capacity": df.loc[i, "容量"]
    }
    edges.append(edge)

plt.figure(figsize=(15,15))
G = nx.DiGraph()
for edge in edges:
    G.add_edge(edge["tail"], edge["head"], weight=edge["length"])

pos = nx.spring_layout(G)
nx.draw(G, pos, with_labels=True)
labels = nx.get_edge_attributes(G, "weight")
nx.draw_networkx_edge_labels(G, pos, edge_labels=labels)
#nx.draw_networkx_edge_labels(G, pos, edge_labels=labels, label_pos=0.3)
plt.show()

all_pairs = nx.all_pairs_dijkstra(G)
rows = []
for start_node, (dist_dict, path_dict) in all_pairs:
    for end_node, dist in dist_dict.items():
        path_nodes = path_dict[end_node]
        path_edges = []
        for i in range(len(path_nodes)-1):
            tail = path_nodes[i]
            head = path_nodes[i+1]
            for edge in edges:
                if edge["tail"] == tail and edge["head"] == head:
                    path_edges.append(edge["id"])
                    break
        path_edges_str = ",".join(path_edges)
        rows.append({'起始节点': start_node, '终止节点': end_node, '最短路径长度': dist, '经过的边': path_edges_str})

df_result = pd.DataFrame(rows)
df_result.to_excel('all_pairs.xlsx', index=False)

修改后的代码中，我们使用 `nx.all_pairs_dijkstra` 函数计算所有最短路径，并且在计算过程中记录了每个最短路径经过的边的编号。然后将其一起写入Excel文件中。