python+pygraphviz实现二叉树的绘制_python graphviz节点采用...

pygraphviz实现了对graphviz的封装，可以轻松地实现流程图等图形的绘制，支持的图形样式包括dot、neato、fdp等，绘制二叉树需要用到dot格式，更多的dot语言以及以下代码中add_node函数和add_edge函数需要用到的参数详见dot官网或者dot手册

安装教程见链接
二叉树的绘制python代码

# coding=utf-8
import pygraphviz as pgv
graph = pgv.AGraph()
graph.add_node('nodeA', shape='circle', label='A', style='bold')
graph.add_node('nodeB', shape='circle', label='B', style='bold')
graph.add_node('nodeC', shape='circle', label='C', style='bold')
graph.add_node('nodeD', shape='circle', label='D', style='bold')
graph.add_node('nodeE', shape='circle', label='E', style='bold')
graph.add_node('nodeF', shape='circle', label='F', style='bold')
graph.add_edge('nodeA', 'nodeB', style='bold', tailport='sw') # sw是从节点的西南方向引出边
graph.add_edge('nodeB', 'nodeC', style='bold', tailport='sw')
graph.add_edge('nodeB', 'nodeD', style='bold', tailport='se') # sw是从节点的东南方向引出边
graph.add_edge('nodeD', 'nodeE', style='bold', tailport='sw')
graph.add_edge('nodeA', 'nodeF', style='bold', tailport='se')
graph.layout('dot')
graph.draw('.\\bin_tree.jpg')
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以上代码得到图形
为了使二叉树伸展性更好，可以对所有的空指针域添加不可见边

# coding=utf-8
import pygraphviz as pgv
graph = pgv.AGraph()
graph.add_node('nodeA', shape='circle', label='A', style='bold') # bold参数是加粗
graph.add_node('nodeB', shape='circle', label='B', style='bold')
graph.add_node('nodeC', shape='circle', label='C', style='bold')
graph.add_node('nodeD', shape='circle', label='D', style='bold')
graph.add_node('nodeE', shape='circle', label='E', style='bold')
graph.add_node('nodeF', shape='circle', label='F', style='bold')
graph.add_node('nodeCL', style='invis') # 添加不可见节点, 使得二叉树伸展性更好
graph.add_node('nodeCR', style='invis')
graph.add_node('nodeEL', style='invis')
graph.add_node('nodeER', style='invis')
graph.add_node('nodeDR', style='invis')
graph.add_node('nodeFL', style='invis')
graph.add_node('nodeFR', style='invis')
graph.add_edge('nodeA', 'nodeB', style='bold', tailport='sw')
graph.add_edge('nodeB', 'nodeC', style='bold', tailport='sw')
graph.add_edge('nodeB', 'nodeD', style='bold', tailport='se')
graph.add_edge('nodeD', 'nodeE', style='bold', tailport='sw')
graph.add_edge('nodeA', 'nodeF', style='bold', tailport='se')
graph.add_edge('nodeC', 'nodeCL', style='invis', tailport='sw') # 添加不可见边
graph.add_edge('nodeC', 'nodeCR', style='invis', tailport='se')
graph.add_edge('nodeE', 'nodeEL', style='invis', tailport='sw')
graph.add_edge('nodeE', 'nodeER', style='invis', tailport='sw')
graph.add_edge('nodeD', 'nodeDR', style='invis', tailport='se')
graph.add_edge('nodeF', 'nodeFL', style='invis', tailport='sw')
graph.add_edge('nodeF', 'nodeFR', style='invis', tailport='se')
graph.layout('dot')
graph.draw('.\\bin_tree.jpg')
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一些更为复杂的图形：