我有下面的代码来加载数据：
from pymnet import *
import pandas as pd
nodes_id = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 1, 2, 3, 'aa', 'bb', 'cc']
layers = [1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 3, 3, 3]
nodes = {'nodes': nodes_id, 'layers': layers}
df_nodes = pd.DataFrame(nodes)
to = ['b', 'c', 'd', 'f', 1, 2, 3, 'bb', 'cc', 2, 3, 'a', 'g']
from_edges = ['a', 'a', 'b', 'e', 'a', 'b', 'e', 'aa', 'aa', 'aa', 1, 2, 3]
edges = …