从现有的不可变subgraph_view创建可变有向图

Question

我做以下几件事。但是，当我试图修改new_graph中的节点时，就会得到一个TypeError: 'AtlasView' object does not support item assignment

    def get_my_nodes(source=None, distance=0):
        pre = [n for n in nx.dfs_preorder_nodes(G, source=source, depth_limit=distance)]
        post = [n for n in nx.dfs_preorder_nodes(G.reverse(), source=source, depth_limit=distance)]
        return set(pre + post)

    my_nodes = get_my_nodes(n, distance=dist)

    def filter_node(n):
        if n in my_nodes:
            return True
        return False

    subgraph_view = nx.subgraph_view(G, filter_node=filter_node)
    
    new_graph = nx.DiGraph(subgraph_view.copy())
    new_graph['my_node']['weight'] = 25  # <- this raises a TypeError: 'AtlasView' object does not support item assignment

Answer 1

您正在访问AtlasView，它仅在内部级别上读取(请参阅医生..。)。

最简单的解决方案是使用nx.set_node_attributes

def get_my_nodes(source=None, distance=0):
    pre = [n for n in nx.dfs_preorder_nodes(G, source=source, depth_limit=distance)]
    post = [n for n in nx.dfs_preorder_nodes(G.reverse(), source=source, depth_limit=distance)]
    return set(pre + post)

my_nodes = get_my_nodes(n, distance=dist)

def filter_node(n):
    if n in my_nodes:
        return True
    return False

subgraph_view = nx.subgraph_view(G, filter_node=filter_node)

new_graph = nx.DiGraph(subgraph_view.copy())

#new_graph['my_node'] is an AtlasView object (read only)

nx.set_node_attributes(new_graph, {'my_node': 25}, name='weight')