Python Networkx with_pandas_edgelist：边缘没有采用正确的颜色，同时指定节点位置

Question

我对 Python 很陌生，并开始学习 networkx 来绘制道路网络图。我必须指定节点位置。边缘颜色应取决于边缘的权重。我尝试使用 pandas 数据框来生成边缘。未指定位置时，边缘颜色可以正常工作。附上代码。

import pandas as pd
import networkx as nx
import matplotlib.pyplot as plt

# Necessary file-paths
l1 = 'file1.xlsx'
l2 = "file2.xlsx"

n1 = pd.read_excel(l1)
n1.head(10)

n2 = pd.read_excel(l2)
n2.head(2)

# Building graph
G = nx.from_pandas_edgelist(n1, 'Start Node', 'End Node', create_using=nx.Graph())

# Defining positions
pos = {}
for n in G.nodes():
    i = n2[n2["Nodes"] == n].index[0]
    pos[n] = (n2.loc[i, "x"], n2.loc[i, "y"])

# Plot the Graph
nx.draw(G, pos, with_labels=True, node_color='pink', node_size=30, alpha=0.8, font_size=2,
        edge_color=n1['Capacity'], width=1.0, figsize = (18,18), style="solid", edge_cmap=plt.cm.jet)

# Save the Figure
plt.savefig('Network.png', dpi=1000, facecolor='w', edgecolor='w',orientation='portrait',  
            papertype=None, format=None,transparent=False, bbox_inches=None, pad_inches=0.1)

但是，颜色不遵循容量值。我将分享一个例子。 这是它不必要地改变颜色的情况

另一个例子 - 这里的颜色应该改变，但它没有

The excel files are here for reference

另外，如果您能建议如何为此添加颜色条，那就太好了。

Answer 1

import networkx as nx

# dummy data, Graph and positions
df = pd.DataFrame({
    'node1': np.random.choice([*'ABCDEFGHIJKL'], 10, replace=True),
    'node2': np.random.choice([*'ABCDEFGHIJKL'], 10, replace=True),
    'Capacity': np.random.rand(10)
})
G = nx.from_pandas_edgelist(df, source='node1', target='node2', edge_attr='Capacity')
pos = nx.spring_layout(G)

# extract the edge weight
edge_colors = [a['Capacity'] for u,v,a in G.edges(data=True)]

# draw nodes and edges separately. allows using colormap for edges.
nx.draw_networkx_nodes(G, pos=pos)
nx.draw_networkx_edges(G, pos=pos, edge_color=edge_colors, edge_cmap=plt.cm.viridis, edge_vmin=0, edge_vmax=np.max(edge_colors), width=5)
nx.draw_networkx_labels(G, pos=pos);