使用Python，maplotlib绘制树型有向层级结构图

1. 效果图
2. 源码
- 2.1 plotTree.py绘制层级结构及不同样式
- 2.2 plotArrow.py 支持的所有箭头样式
参考

前俩篇博客介绍了
1. 使用Python，networkx对卡勒德胡赛尼三部曲之《群山回唱》人物关系图谱绘制
2. 使用Python，networkx绘制有向层级结构图
3. 使用Python，maplotlib绘制树型有向层级结构图这篇博客是绘制层级结构图三部曲最后一篇。

1. 效果图

按父子层级结构绘制图形，并标记之间的关联关系，并根据不同标签绘制不同颜色箭头（hello的蓝色箭头，bad的红色箭头，默认绿色箭头），效果图如下：
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同样是表达层级结构关系，可以很明显的看出来这比上篇博客使用networkx绘制的层级图要清楚很多，一目了然。
在这里插入图片描述

不同箭头样式：
在这里插入图片描述

支持的所有箭头及箭头弯曲程度样式如下：
在这里插入图片描述

2. 源码

2.1 plotTree.py绘制层级结构及不同样式

# python plotTree.py
# 绘制层级结构图，并根据标签值对树绘制不同颜色import matplotlib.pyplot as pltplt.rcParams['backend'] = 'TkAgg'
decisionNode = dict(boxstyle="sawtooth", fc="0.8")
leafNode = dict(boxstyle="round4", fc="0.8")def getNumLeafs(myTree):numLeafs = 0firstStr = list(myTree.keys())[0]secondDict = myTree[firstStr]for key in secondDict.keys():if type(secondDict[key]).__name__ == 'dict':  # test to see if the nodes are dictonaires, if not they are leaf nodesnumLeafs += getNumLeafs(secondDict[key])else:numLeafs += 1return numLeafsdef getTreeDepth(myTree):maxDepth = 0firstStr = list(myTree.keys())[0]secondDict = myTree[firstStr]for key in secondDict.keys():if type(secondDict[key]).__name__ == 'dict':  # test to see if the nodes are dictonaires, if not they are leaf nodesthisDepth = 1 + getTreeDepth(secondDict[key])else:thisDepth = 1if thisDepth > maxDepth: maxDepth = thisDepthreturn maxDepthdef plotNode(nodeTxt, centerPt, parentPt, nodeType, color):# 分别表示箭头的样式，俩边距离边框的值，以及箭头线的弯曲程度，箭头的颜色arrow_args = dict(arrowstyle="<-", shrinkA=10, shrinkB=10, patchA=None, patchB=None, connectionstyle="arc3,rad=0.3",color=color)arrow_args = dict(arrowstyle="<-", shrinkA=10, shrinkB=10, patchA=None, patchB=None, connectionstyle="arc3, rad = 0.",color=color)createPlot.ax1.annotate(nodeTxt, xy=parentPt, xycoords='axes fraction',xytext=centerPt, textcoords='axes fraction',va="center", ha="center", bbox=nodeType, arrowprops=arrow_args)def plotMidText(cntrPt, parentPt, txtString):xMid = (parentPt[0] - cntrPt[0]) / 2.0 + cntrPt[0]yMid = (parentPt[1] - cntrPt[1]) / 2.0 + cntrPt[1]createPlot.ax1.text(xMid, yMid, txtString, va="center", ha="center", rotation=30)def getArrowColors(parentNode, firstStr, edgeDict):key = parentNode + '->' + firstStrif not edgeDict.__contains__(key):color = 'black'elif edgeDict[key].__contains__('hello'):color = 'blue'elif edgeDict[key].__contains__('bad'):color = 'red'else:color = 'green'return colordef getArrowAttrTxt(parentNode, firstStr, edgeDict):key = parentNode + '->' + firstStrif not edgeDict.__contains__(key):return ''return edgeDict[key]def plotTree(myTree, parentPt, parentNode, nodeTxt):numLeafs = getNumLeafs(myTree)depth = getTreeDepth(myTree)firstStr = list(myTree.keys())[0]cntrPt = (plotTree.xOff + (1.0 + float(numLeafs)) / 2.0 / plotTree.totalW, plotTree.yOff)plotMidText(cntrPt, parentPt, getArrowAttrTxt(parentNode, firstStr, edgeDict))plotNode(firstStr, cntrPt, parentPt, decisionNode, getArrowColors(parentNode, firstStr, edgeDict))secondDict = myTree[firstStr]plotTree.yOff = plotTree.yOff - 1.0 / plotTree.totalDfor key in secondDict.keys():if type(secondDict[key]).__name__ == 'dict':print("++++++++++++: ", key, firstStr)plotTree(secondDict[key], cntrPt, firstStr, str(key))  # recursionelse:print('----: ', secondDict[key], firstStr, key)plotTree.xOff = plotTree.xOff + 1.0 / plotTree.totalWplotNode(secondDict[key], (plotTree.xOff, plotTree.yOff), cntrPt, leafNode,getArrowColors(firstStr, secondDict[key], edgeDict))plotMidText((plotTree.xOff, plotTree.yOff), cntrPt, getArrowAttrTxt(firstStr, secondDict[key], edgeDict))plotTree.yOff = plotTree.yOff + 1.0 / plotTree.totalDdef createPlot(inTree):fig = plt.figure(1, facecolor='white')fig.clf()axprops = dict(xticks=[], yticks=[])createPlot.ax1 = plt.subplot(111, frameon=False, **axprops)  # no ticks# createPlot.ax1 = plt.subplot(111, frameon=False) #ticks for demo puropsesplotTree.totalW = float(getNumLeafs(inTree))plotTree.totalD = float(getTreeDepth(inTree))plotTree.xOff = -0.5 / plotTree.totalW;plotTree.yOff = 1.0;plotTree(inTree, (0.5, 1.0), 'A', '')plt.show()def retrieveTree(i):listOfTrees = [{'no surfacing': {0: 'no', 1: {'flippers': {0: 'no', 1: 'yes'}}}},{'no surfacing': {0: 'no', 1: {'flippers': {0: {'head': {0: 'no', 1: 'yes'}}, 1: 'no'}}}}]return listOfTrees[i]def getTree(treeDict, nood):retrieveTree = {}for i, val in enumerate(treeDict[nood]):print(i, nood, val)if (treeDict.__contains__(val)):subTree = {}subTree[val] = getTree(treeDict, val)retrieveTree[i] = subTreeelse:retrieveTree[i] = valreturn retrieveTreedef getRetrieveTree():treeDict = {}edgeDict = {}with open("res/tree.txt", 'r', encoding='utf-8', errors='ignore') as f:data = f.readlines()for i, line in enumerate(data):parentNode = line.split(",")[0]childNode = line.split(",")[1]edgeDict[parentNode + "->" + childNode] = line.split(",")[2]# print(parentNode, childNode)if not treeDict.__contains__(parentNode):treeDict[parentNode] = set()treeDict[parentNode].add(childNode)print(treeDict)treeDict0 = {}treeDict0['A'] = getTree(treeDict, 'A')# print(treeDict0)return (treeDict0, edgeDict)# treeDemo = retrieveTree(1)
# print(treeDemo)
# createPlot(treeDemo)
(treeDict, edgeDict) = getRetrieveTree()
print(treeDict)
createPlot(treeDict)

2.2 plotArrow.py 支持的所有箭头样式

# python plotArrow.py
from matplotlib import pyplot as pltprint(plt.rcParams['backend'])  # module://backend_interagg
plt.rcParams['backend'] = 'TkAgg'def demo_con_style(ax, connectionstyle):x1, y1 = 0.3, 0.2x2, y2 = 0.8, 0.6ax.plot([x1, x2], [y1, y2], ".")ax.annotate("", xy=(x1, y1), xycoords='data',xytext=(x2, y2), textcoords='data',arrowprops=dict(arrowstyle="->", color="0.5",shrinkA=5, shrinkB=5,patchA=None, patchB=None,connectionstyle=connectionstyle,),)ax.text(.05, .95, connectionstyle.replace(",", ",\n"),transform=ax.transAxes, ha="left", va="top")fig, axs = plt.subplots(3, 5, figsize=(8, 4.8))
demo_con_style(axs[0, 0], "angle3, angleA = 90, angleB = 0")
demo_con_style(axs[1, 0], "angle3, angleA = 0, angleB = 90")
demo_con_style(axs[0, 1], "arc3, rad = 0.")
demo_con_style(axs[1, 1], "arc3, rad = 0.3")
demo_con_style(axs[2, 1], "arc3, rad = -0.3")
demo_con_style(axs[0, 2], "angle, angleA = -90, angleB = 180, rad = 0")
demo_con_style(axs[1, 2], "angle, angleA = -90, angleB = 180, rad = 5")
demo_con_style(axs[2, 2], "angle, angleA = -90, angleB = 10, rad = 5")
demo_con_style(axs[0, 3], "arc, angleA = -90, angleB = 0, armA = 30, armB = 30, rad = 0")
demo_con_style(axs[1, 3], "arc, angleA = -90, angleB = 0, armA = 30, armB = 30, rad = 5")
demo_con_style(axs[2, 3], "arc, angleA = -90, angleB = 0, armA = 0, armB = 40, rad = 0")
demo_con_style(axs[0, 4], "bar, fraction = 0.3")
demo_con_style(axs[1, 4], "bar, fraction = -0.3")
demo_con_style(axs[2, 4], "bar, angle = 180, fraction = -0.2")for ax in axs.flat:ax.set(xlim=(0, 1), ylim=(0, 1), xticks=[], yticks=[], aspect=1)
fig.tight_layout(pad=0.2)plt.show()