Getting AttributeError while exporting Networkx Graph to JSON

Question

I am trying to generate JSON file for my graph using below code.

G = nx.DiGraph()
G.add_nodes_from(['A', 'B', 'C', 'D'])
G.add_edges_from([('A', 'B'), ('B', 'C'), ('B', 'D')])
type = 'layer'
for node in G.nodes():
    if node in ('A', 'B'):
        G[node][type] = '1'
    else:
        G[node][type] = '2'
d = json_graph.node_link_data(G)
json.dump(d, open('data.json','w'))

it's throwing error AttributeError: 'str' object has no attribute 'items'

If I remove the attribute('layer') from my graph I am able to save in JSON format.My aim is to save the graph with attributes. Is this the right way to create JSON using networkx ??

Update : Unable to add whole error in comment, so adding in main.

AttributeError Traceback (most recent call last) in ()

      8     else:
      9         G[node][type] = '2'
---> 10 d = json_graph.node_link_data(G)
     11 json.dump(d, open('data.json','w'))

C:\Users\ljose\AppData\Local\Continuum\Anaconda3\lib\site-packages\networkx\readwrite\json_graph\node_link.py in node_link_data(G, attrs)

     90             dict(chain(d.items(),
     91                        [(source, mapping[u]), (target, mapping[v])]))
---> 92             for u, v, d in G.edges_iter(data=True)]
     93 
     94     return data

C:\Users\ljose\AppData\Local\Continuum\Anaconda3\lib\site-packages\networkx\readwrite\json_graph\node_link.py in (.0)

     90             dict(chain(d.items(),
     91                        [(source, mapping[u]), (target, mapping[v])]))
---> 92             for u, v, d in G.edges_iter(data=True)]
     93 
     94     return data

AttributeError: 'str' object has no attribute 'items'

rodgdor rodgdor · Accepted Answer · 2017-12-11T22:03:39

The error comes from the fact that G[node][type] = 1 is actually assigning a weight 1 to edge (node, type) instead of assigning attribute type to node node value 1. The following should fix it:

G = nx.DiGraph()
G.add_nodes_from(['A', 'B', 'C', 'D'])
G.add_edges_from([('A', 'B'), ('B', 'C'), ('B', 'D')])
type = 'layer'
for node in G.nodes():
    if node in ('A', 'B'):
        G.node[node][type] = '1'
    else:
        G.node[node][type] = '2'
d = json_graph.node_link_data(G)

Getting AttributeError while exporting Networkx Graph to JSON

Update : Unable to add whole error in comment, so adding in main.

1 Answers