试试看：

import pandas as pd
import networkx as nx

df = pd.read_clipboard()
print(df)

输出量：

topic neighbor
0     K       Kl
1     K       Pr
2    Kl       TS
3    Pr       Kl
4    Pr       Pr

使用source和target参数：

G = nx.from_pandas_edgelist(df, source='topic', target='neighbor')
nx.draw_networkx(G)

输出量：

是，从 Dataframe 创建无定向网络需要指定源和目标。
这不是必须的，但是为了确保图是无向的，可以指定create_using kwarg：

from networkx import Graph, from_pandas_edgelist

df = ...

# note that Graph is the default setting, so specifying
# create_using=Graph is optional
G = from_pandas_edgelist(df, "topic", "neighbor", create_using=Graph)

print(G.is_directed())
# False