Question

我正在使用字典，但出现以下错误

'>' not supported between instances of 'dict' and 'dict'

我知道Python 2.7和3.x版本的字典存在一些问题。

print("number of nodes %d" % G.number_of_nodes())
print("number of edges %d" % G.number_of_edges())
print("Graph is connected?: %s" % nx.is_connected(G))
print("Number of connected components: %s" % nx.number_connected_components(G))
print("Size of connected componnents: %s" % [len(cc) for cc in nx.connected_components(G)])
print("Network Analysis will be performed on the largest cc from now on") 
largest_cc = max(nx.connected_component_subgraphs(G), key=len) 

dict_communities={}
num_communities=max([y for x,y in largest_cc.nodes(data=True)]).values()[0]
for i in range (1,num_communities+1):
    dict_communities[i] = [x for x,y in largest_cc.nodes(data=True) if y['community']==i]

TypeError                                 Traceback (most recent call last)
<ipython-input-12-fd6e5cb0ddb5> in <module>
      1 dict_communities={}
----> 2 num_communities=max([y for x,y in largest_cc.nodes(data=True)])[0]
      3 for i in range (1,num_communities+1):
      4     dict_communities[i] = [x for x,y in largest_cc.nodes(data=True) if y['community']==i]

TypeError: '>' not supported between instances of 'dict' and 'dict'

Answer 1

在networkx中，graph.nodes(data=True)返回带有节点参数的node_id-dicts元组的列表。但是在Python中，字典无法比较（调用max函数时您试图比较它们）。您应该使用另一种方式来完成此操作，例如使用如下代码提取每个节点的特定参数：

max([y['some_argument'] for x,y in largest_cc.nodes(data=True)])
           ^
           |
Add it ----+

这里是示例：

我们创建一个随机图，并在参数'arg'中填充随机数：

import networkx as nx
import random

G = nx.gnp_random_graph(10,0.3,directed=True)
for node in G.nodes:
    G.nodes[node]['arg'] = random.randint(1, 10)

然后，我们尝试使用您的代码：

[y for x,y in G.nodes(data=True)]

它返回：

[{'arg': 8},
 {'arg': 5},
 {'arg': 9},
 {'arg': 4},
 {'arg': 8},
 {'arg': 6},
 {'arg': 3},
 {'arg': 2},
 {'arg': 8},
 {'arg': 1}]

而且您无法将这些字典相互比较。

但是如果您要在列表中指定“ arg”：

[y['arg'] for x,y in G.nodes(data=True)]

它将返回：

[8, 1, 5, 3, 10, 5, 7, 10, 1, 2]

您可以选择最大的元素（但不要在行尾写.values()[0]，这会导致错误）：

max([y['arg'] for x,y in G.nodes(data=True)])

10

TypeError：“ dict”和“ dict”的实例之间不支持“>”

1 个答案: