Iterate through node attributes in networkx

Question

I create a graph with networkx and every node has some attributes. So i want to search all nodes for a specific attributes and save every node who has this attribute in a list. I wrote the following code but im getting an error:

for node in G.nodes():
    for attribute in G.node[node]['attributes']:
        if attribute in question:
            setOfUsers.append(node)

With this code im getting the following error:

for attribute in G.node[node]['attributes']:
KeyError: 'attributes'

So i search the forum and i tried something different to fix the problem:

for node, data in G.nodes(data=True):
    if data['attributes'] == question[0]:
        setOfUsers.append(node)

but i have the same error. How can iterate through the attributes?

Update: I add the node attributes with the code below. I read the attributes from a file, i split commas and newline character and then i save list in nodes

for line in file2:
    line = line.strip()
    words = line.split('\t')
    node = int(words[0])
    attributes= words[1]
    splittedAttributes = attributes.split(',')
    if node in G.nodes():
        G.node[node]['attributes'] = splittedAttributes

Are you sure any node has an 'attribute' attribute? If node in G.nodes() is never true, in the line if node in G.nodes(): G.node[node]['attributes'] = splittedAttributes then no node will be assigned an 'attributes' attribute. — unutbu
@anutbu yes i think that this is the problem. I have some nodes that they dont have attributes. How can i fix this? Is it a goof idea to add a space as attribute? — Lee Yaan

Hamed Temsah Hamed Temsah · Accepted Answer · 2018-02-10T14:47:10

are your sure you have added the info to your nodes previously? it seems like networkX doesn't known anything about your 'attributes'. by adding the info i mean something like this:

for node in G.nodes():
    G.node[node]['attributes']= attributes[node]

then you can use your own code to examine them

for node in G.nodes():
    for attribute in G.node[node]['attributes']:
        if attribute in question:
            setOfUsers.append(node)

Iterate through node attributes in networkx

1 Answers