运行湾区路网抗震交通模型代码遇NetworkX DiGraph属性错误求助

Hey there! As someone new to Python, hitting this kind of attribute error with a pre-built model can feel frustrating—but let's work through it step by step. Here are the most likely fixes and debugging steps to try:

1. Check NetworkX Version Compatibility #

This error often pops up when there's a mismatch between the NetworkX version the original researcher used and the one you have installed.

• First, check your current NetworkX version with this command in your terminal:

  pip show networkx
  

• Then, look back at the project's README or documentation—does it specify a required NetworkX version? For example, many older projects rely on NetworkX 2.x, while newer versions (3.x+) have changed internal attributes like _succ (a private attribute used to store successor nodes).
• If versions don't match, uninstall your current version and install the specified one:

  pip uninstall networkx
  pip install networkx==2.8.8  # Replace with the exact version from the README
  

2. Verify the DiGraph Object is Properly Initialized #

Sometimes the error happens because the graph didn't load correctly from the sample data. Add a few quick debug lines right after the code loads the graph:

# Insert this after the graph is loaded/created
import networkx as nx
print(f"Graph type: {type(your_graph_variable)}")  # Replace with your graph's actual variable name
print(f"Does it have _succ attribute? {'_succ' in dir(your_graph_variable)}")

• If the graph type isn't networkx.classes.digraph.DiGraph, that means the data loading step failed—double-check that you're pointing to the correct sample data files as per the README.
• If _succ isn't present, you might be on a newer NetworkX version where this internal attribute was renamed or removed. Use the public API instead: for example, replace direct access to graph._succ[node] with graph.successors(node) or graph.adj[node].

3. Pinpoint the Exact Code Line Triggering the Error #

Look at the full error traceback (the red text in your terminal) to find which line of code is throwing the AttributeError. For example:

AttributeError: 'DiGraph' object has no attribute '_succ'
File "model.py", line 123, in calculate_traffic
for neighbor in self.graph._succ[node]:

If the code is directly accessing _succ (a private internal attribute), that's bad practice and breaks across NetworkX versions. Modify that line to use the public method:

# Replace this
for neighbor in self.graph._succ[node]:
# With this
for neighbor in self.graph.successors(node):

4. Test with a Minimal DiGraph #

To rule out broader NetworkX issues, create a tiny test DiGraph in a separate script:

import networkx as nx
test_graph = nx.DiGraph()
test_graph.add_edge("A", "B")
test_graph.add_edge("B", "C")

# Try accessing successors using the public API
print(list(test_graph.successors("A")))  # Should output ['B']

If this works fine, the problem is specific to how the sample data is being loaded or processed in the original model code—not NetworkX itself.

内容的提问来源于stack exchange，提问作者Gitanjali