AttributeError: 'set' 对象没有与 NetworkX 一起使用的属性 'number_of_nodes'

Question

I'm new to NetworkX, using NetworkX 2.5 and have some problems with deprecated code. The code is extracted from here . I tried fixing some deprecated functions but can't get the code to work. I also don't understand how connected_components function works.

panama_nodes = panama.nodes()
relabel = {}

for f, cc, name in NODES:
    with open(f,encoding='utf8') as infile:
        kind = f.split(".")[0]
        data = csv.DictReader(infile)
        names_countries = {node["node_id"] :
                           (node[name].strip().upper(), node[cc])
                           for node in data
                           if node["node_id"] in panama_nodes}
    names =     {nid: values[0] for nid, values in names_countries.items()}
    countries = {nid: values[1] for nid, values in names_countries.items()}
    kinds =     {nid: kind      for nid, _      in names_countries.items()}
    nx.set_node_attributes(panama, countries, "countries")
    nx.set_node_attributes(panama, kinds, "kind")
    relabel.update(names)

nx.relabel_nodes(panama, relabel, copy=False)

if "ISSUES OF:" in panama:
    panama.remove_node("ISSUES OF:")

if "" in panama:
    panama.remove_node("")

print(nx.number_of_nodes(panama), nx.number_of_edges(panama))

components = [p.nodes() for p in nx.connected_components(panama)
              if nx.number_of_nodes(p) >= 20
              or nx.number_of_edges(p) >= 20]

panama0 = panama.subgraph(itertools.chain.from_iterable(components))

with open("panama-beneficiary.pickle", "wb") as outfile:
    pickle.dump(panama0, outfile)

These lines of code return an AttributeError:

components = [p.nodes() for p in nx.connected_components(panama)
              if nx.number_of_nodes(p) >= 20
              or nx.number_of_edges(p) >= 20]

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-6-108e98bba596> in <module>
----> 1 components = [p.nodes() for p in nx.connected_components(panama)
      2               if nx.number_of_nodes(p) >= 20
      3               or nx.number_of_edges(p) >= 20]
      4 
      5 panama0 = panama.subgraph(itertools.chain.from_iterable(components))

<ipython-input-6-108e98bba596> in <listcomp>(.0)
      1 components = [p.nodes() for p in nx.connected_components(panama)
----> 2               if nx.number_of_nodes(p) >= 20
      3               or nx.number_of_edges(p) >= 20]
      4 
      5 panama0 = panama.subgraph(itertools.chain.from_iterable(components))

~\AppData\Local\Programs\Python\Python37\lib\site-packages\networkx\classes\function.py in number_of_nodes(G)
     83 def number_of_nodes(G):
     84     """Returns the number of nodes in the graph."""
---> 85     return G.number_of_nodes()
     86 
     87 

AttributeError: 'set' object has no attribute 'number_of_nodes'

Any help is appreciated!

Answer 1

connected_components only retrieves the set of nodes in NetworkX 2.5. If I remember correctly in older version it returned the subgraphs. To adjust the code you need to do the following:

components = [panama.subgraph(p).copy() for p in nx.connected_components(panama)]

# probably you want a list/set instead of a NodeView
components = [list(p.nodes()) for p in components
              if p.number_of_nodes(p) >= 20
              or p.number_of_edges(p) >= 20]

or directly

components = [p for p in nx.connected_components(panama)
              if len(p) >= 20
              or panama.subgraph(p).number_of_edges() >= 20]