KeyError: 'Head nodes supplied to generator contain IDs not found in graph'

I was trying to implement Stellargraph - Directed GraphSAGE, but then following error occurred: KeyError: ‘Head nodes supplied to generator contain IDs not found in graph’. I don’t know how to fix this.

I made the network by using the following code:

G = nx.Graph()
G.add_nodes_from(list(sample.client.values))
G.add_nodes_from(list(sample.merchant.values))                   
G.add_nodes_from(list(sample.transaction.values))
edgelist1 = list((zip(sample.transaction.values, sample.client.values)))
edgelist2 = list((zip(sample.transaction.values, sample.merchant.values)))
G.add_edges_from(edgelist1)
G.add_edges_from(edgelist2)

Then I split the data in train_data and test_data. I then transform all features to numeric features. I used one-hot encoding to transform the categoric variable ‘country’. Furthermore, I dropped some columns in the train and test data. Moreover, I defined a variable node_features that represents the features used as node attributes (minus the target variable).

Then I transformed the graph into a Stellargraph :

stelgr = sg.StellarDiGraph(G, node_features= node_features)
batch_size = 50; in_samples = [5, 2]; out_samples = [5, 2]
generator = DirectedGraphSAGENodeGenerator(stelgr, batch_size, in_samples, out_samples)
train_gen = generator.flow(train_data, train_targets, shuffle=False)

Then this error occurs:

---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
<ipython-input-49-825ab36d20da> in <module>
----> 1 train_gen = generator.flow(train_data, train_targets, shuffle=False)

~\Anaconda3\lib\site-packages\stellargraph\mapper\node_mappers.py in flow(self, node_ids, targets, shuffle)
   1107 
   1108         """
-> 1109         return NodeSequence(self, node_ids, targets, shuffle=shuffle)
   1110 
   1111     def flow_from_dataframe(self, node_targets, shuffle=False):

~\Anaconda3\lib\site-packages\stellargraph\mapper\node_mappers.py in __init__(self, generator, ids, targets, shuffle)
    105         if any(n not in generator.graph for n in ids):
    106             raise KeyError(
--> 107                 "Head nodes supplied to generator contain IDs not found in graph"
    108             )
    109 

KeyError: 'Head nodes supplied to generator contain IDs not found in graph'

[huonw]

0.8.4 has now been released.

[huonw]

Hi @ocesp98, have we addressed your problem here?