class demo():def __init__(self):self.file_path='test.txt'#图文件    def draw_graph(self):G2 = nx.DiGraph()  # 创建：空的 有向图f = open(self.file_path)lines = [l.split() for l in f.readlines() if l.strip()]# print(lines)for i in lines:G2.add_edge(i[0],i[1],weight=i[2])pos = nx.random_layout(G2)  # 用 FR算法排列节点nx.draw(G2, pos, with_labels=True, alpha=0.5)labels = nx.get_edge_attributes(G2, 'weight')nx.draw_networkx_edge_labels(G2, pos, edge_labels=labels)plt.show()

txt文件的格式如下：起点 终点 权值   中间用空格隔开 。至于库，大家自行导一下