在已形成的网络G中，存在节点i与其邻居构成的子图Gi，我们想得到Gi中每个邻居到彼此的最短距离，并求其倒数之和，用python写出

可以使用networkx库中的函数来实现该问题。代码如下：

import networkx as nx

# 构造图G
G = nx.Graph()
G.add_edges_from([(1, 2), (1, 3), (2, 3), (3, 4), (3, 5), (4, 5)])

# 遍历每个节点，计算邻居间的最短距离并求倒数之和
sum_inv_dist = 0
for node in G.nodes():
    neighbors = list(G.neighbors(node))
    subgraph = G.subgraph([node] + neighbors)
    shortest_paths = dict(nx.shortest_path_length(subgraph))
    for i, n1 in enumerate(neighbors):
        for n2 in neighbors[i+1:]:
            dist = shortest_paths[n1][n2]
            sum_inv_dist += 1 / dist

print(sum_inv_dist)

这里构造了一个简单的图G作为例子，可以根据实际情况修改。