python - How to find the number of edges bewteen any two nodes using networkx? -

exist form count number of edges separe 2 nodes, example if have nodes "a", "b", "c" , "d" form "a"-"b"-"c"-"d" (where "-" edge) need count edges between "a" , "d".

the real example follow. have big graph, in link can see image https://drive.google.com/file/d/0b7gayk8mggtccvhrmncym0vmc2c/view?usp=sharing

graph have 2806 nodes in case, , need know example how many edges separe node 608 of 616. thought number_of_edges function can me, think returns if 2 nodes connected or not (because returns 1 or 0 in code this)

    k in id1: #id1 list of nodes         l in id2: #id2 list of nodes             print graph.number_of_edges(k,l) 

without knowing have attempted , without example graph give simple example. might clear things you.

i make 4 node, 4 edge graph adjacency matrix using newtworkx , numpy.

import matplotlib.pyplot plt import networkx nx import numpy np  adjacency_matrix = np.array([[0,1,0,1], [1,0,1,0], [0,1,0,1], [1,0,1,0]]) print adjacency_matrix 

this prints our graph:

[[0 1 0 1]  [1 0 1 0]  [0 1 0 1]  [1 0 1 0]] 

now feed adjacency matrix networkx such:

rows, cols = np.where(adjacency_matrix == 1) edges = zip(rows.tolist(), cols.tolist()) gr = nx.graph() gr.add_edges_from(edges) 

plot it:

nx.draw_networkx(gr) plt.show()  

now can @ nodes connected 1 by:

print gr.number_of_edges(0, 1) # has edge print gr.number_of_edges(2, 0) # no edge between 2 , 0 

and expected prints:

1 0 

so if getting 0 number_of_edges(a, b) , b not adjacent (not edge between them).

[edit: if want find paths between 2 , 0 can following

for path in nx.all_simple_paths(gr, source=2, target=0):     print(path) # prints # [2, 1, 0] # [2, 3, 0] 

or find shortest path:

p = nx.shortest_path(gr,source=2, target=0) # [2, 1, 0] 

in case say:

num_edges = len(p) - 1 # num_edges = 2 

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