Python: 如何使用graphviz套件繪製U型流程圖? with g.subgraph() as s: s.attr(rank=’same’)

# -*- coding: utf-8 -*-
"""
Created on Mon Nov 10 15:35:58 2024

@author: SavingKing
"""


from graphviz import Digraph

# 创建一个有向图，设置其布局为从左到右
g = Digraph('G', filename='process_graph.gv', format='png', engine='dot')
g.attr(rankdir='LR')
"""g = Digraph('G', filename='process_graph.gv', format='png', engine='dot', 
graph_attr={'rankdir': 'LR'})
"""

# 添加节点，替换原有节点名称为A, B, C, ...
g.node('A', 'A ')
g.node('B', 'B ')
g.node('C', 'C ')
g.node('D', 'D ')
g.node('E', 'E ')
g.node('F', 'F ')
g.node('G', 'G ')
g.node('H', 'H ')
g.node('I', 'I ')

# 添加边，根据流程逐步连接节点
g.edge('A', 'B')
g.edge('B', 'C')
g.edge('C', 'D')
g.edge('D', 'E')
g.edge('E', 'F')
g.edge('F', 'G')
g.edge('G', 'H')
g.edge('H', 'I')

# 创建子图以设置特定节点的排列
# 将D, E, F在同一水平线上
with g.subgraph() as s:
    s.attr(rank='same')
    s.node('D')
    s.node('E')
    s.node('F')

# 将C和G在同一水平线上
with g.subgraph() as s:
    s.attr(rank='same')
    s.node('C')
    s.node('G')

# 将B和H在同一水平线上
with g.subgraph() as s:
    s.attr(rank='same')
    s.node('B')
    s.node('H')

# 将A和I在同一水平线上
with g.subgraph() as s:
    s.attr(rank='same')
    s.node('A')
    s.node('I')

# 渲染图形
g.render('process_graph', view=True)

graph_attr={'rankdir': 'LR'}