Storing and Accessing node attributes python networkx
As you say, it's just a matter of adding the attributes when adding the nodes to the graph
G.add_node('abc', dob=1185, pob='usa', dayob='monday')
or as a dictionary
G.add_node('abc', {'dob': 1185, 'pob': 'usa', 'dayob': 'monday'})
To access the attributes, just access them as you would with any dictionary
G.node['abc']['dob'] # 1185
G.node['abc']['pob'] # usa
G.node['abc']['dayob'] # monday
You say you want to look at attributes for connected nodes. Here's a small example on how that could be accomplished.
for n1, n2 in G.edges_iter():
print G.node[n1]['dob'], G.node[n2]['dob']
print G.node[n1]['pob'], G.node[n2]['pob']
# Etc.
As of networkx 2.0, G.edges_iter() has been replaced with G.edges(). This also applies to nodes. We set data=True
to access attributes. The code is now:
for n1, n2 in list(G.edges(data=True)):
print G.node[n1]['dob'], G.node[n2]['dob']
print G.node[n1]['pob'], G.node[n2]['pob']
# Etc.
NOTE: In networkx 2.4, G.node[]
has been replaced with G.nodes[]
.
Additionally, you don't have to just assign the attributes when the node is added. Even after it's been added you can still set them directly.
import networkx as nx
G=nx.Graph()
G.add_edge(1,2)
#see comment below code for recent versions of networkx.
G.nodes[1]['name'] = 'alpha'
G.nodes[2]['name'] = 'omega'
G.nodes[1]['name']
> 'alpha'
Note: For versions before 2.4, use G.node[]
instead of G.nodes[]
. See deprecation notes.
You can also use set_node_attributes
(documentation) which will let you set an attribute for multiple nodes at the same time:
edit
#use the next line if it's networkx version 1.x
#nx.set_node_attributes(G, 'cost', {1:3.5, 2:56})
#use the next line if it's networkx version 2.x
#nx.set_node_attributes(G, {1:3.5, 2:56}, 'cost')
#or for something that works for 1.x or 2.x
nx.set_node_attributes(G, values = {1:3.5, 2:56}, name='cost')
G.node[1]['cost']
> 3.5
Similar approaches can be used to set edge attributes.