import matplotlib.pyplot as plt

decisionNode = dict(boxstyle="sawtooth",fc="0.8")
leafNode = dict(boxstyle="round4",fc="0.8")
arrow_args = dict(arrowstyle="<-")

def plotNode(nodeTxt, centerPt, parentPt, nodeType):
    createPlot.ax1.annotata(nodeTxt,xy=parentPt,\
xycoords='axes fraction',\
xytext = centerPt,textcoords = 'axes fraction',\
va = "center",ha = "center",bbox = nodeType,arrowprops = arrow_args)

def createPlot():
    fig = plt.figure(1,facecolor='white')
    fig.clf()
    createPlot().ax1 = plt.subplot(111, frameon = False)
    plotNode(U'决策节点',(0.5,0.1),(0.1,0.5),decisionNode)
    plotNode(U'叶节点',(0.8,0.1),(0.3,0.8),leafNode)
    plt.show()
