CODEWITHSUNDEEP
pythonpython-3.xnetworkx
Saran
Saran

Reputation: 1844

ValueError: not enough values to unpack (expected 2, got 1) NetworkX python 3

The error reported

Python3.5.2\lib\site-packages\networkx\drawing\nx_pylab.py", 
line 836, in draw_networkx_edge_labels for (n1, n2), label in labels.items():
ValueError: not enough values to unpack (expected 2, got 1)
Code 
map_paths_reduced =  [(0, 75), (75, 38), (38, 86), (86, 119), (119, 85), (85, 44), (44, 65), (65, 127), (127, 106), (106, 31)]
edge_labels_dict_reduced =  {'7': '27.0', '4': '31.0', '2': '17.0', '0': '12.0', '6': '13.0', '1': '16.0', '8': '8.0', '9': '34.0', '3': '6.0', '5': '45.0'}

where, len(edge_labels) = 150

G = nx.DiGraph()
G.add_nodes_from(range(len(edge_labels)+1))
black_edges = [edge for edge in G.edges()]
pos = nx.random_layout(G)
G.add_edges_from(map_paths_reduced)

nx.draw_networkx_nodes(G, pos, cmap=plt.get_cmap('jet'), node_size=100)
nx.draw_networkx_labels(G, pos, font_size=1)
nx.draw_networkx_edges(G, pos, edgelist=black_edges, arrows=True)
nx.draw_networkx_edge_labels(G, pos, edge_labels=edge_labels_dict_reduced) ##ERROR REPORTED HERE
nx.draw_networkx(G, pos, arrows=True)
return plt.show()

When i pass the edge labels dictionary inside nx.draw_networkx_edge_labels using "labels" argument instead of "edge_labels", it shows empty dictionaries as shown in picture. But i am looking for edge labels with key:value entries. drwa_networkx_edge_labels(G,pos,labels = edge_labels_dict_reduced)

Upvotes: 1

Views: 2124

Answers (1)

Martijn Pieters
Martijn Pieters

Reputation: 1123710

The documentation for draw_networkx_edge_labels states that the edge_labels argument requires a dictionary where the keys are tuples with two elements:

edge_labels (dictionary) – Edge labels in a dictionary keyed by edge two-tuple of text labels (default=None). Only labels for the keys in the dictionary are drawn.

Your keys are single strings.

The tuples represent edges; in your graph those are tuples of integers, listed in map_paths_reduced; your label keys must match those edges.

Upvotes: 1

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