Python matplotlib绘图无法显示中文的问题

在python中，默认情况下是无法显示中文的，如下代码：

1. import matplotlib.pyplot as plt
3. # 定义文本框和箭头格式
4. decisionNode = dict(boxstyle = "sawtooth", fc = "0.8")
5. leafNode = dict(boxstyle = "round4", fc = "0.8")
6. arrow_args = dict(arrowstyle = "<-")
8. # 绘制带箭头的注解
9. def plotNode(nodeTxt, centerPt, parentPt, nodeType) :
10. createPlot.ax1.annotate(nodeTxt, xy = parentPt, xycoords = 'axes fraction', xytext = centerPt, textcoords = 'axes fraction', va = 'center', ha = 'center', bbox = nodeType, arrowprops = arrow_args)
12. def createPlot() :
13. fig = plt.figure(1, facecolor='white')
14. fig.clf()
15. createPlot.ax1 = plt.subplot(111, frameon = False)
16. plotNode(U'决策节点', (0.5, 0.1), (0.1, 0.5), decisionNode)
17. plotNode(U'叶节点', (0.8, 0.1), (0.3, 0.8), leafNode)
18. plt.show()
20. createPlot()

得到图像如下：

产生中文乱码的原因就是字体的默认设置中并没有中文字体，我们只要手动添加中文字体的名称就可以了

手动增加如下代码

1. from pylab import *
2. mpl.rcParams['font.sans-serif'] = ['SimHei']

源代码修改如下：

1. import matplotlib.pyplot as plt
3. from pylab import *
4. mpl.rcParams['font.sans-serif'] = ['SimHei']
6. # 定义文本框和箭头格式
7. decisionNode = dict(boxstyle = "sawtooth", fc = "0.8")
8. leafNode = dict(boxstyle = "round4", fc = "0.8")
9. arrow_args = dict(arrowstyle = "<-")
11. # 绘制带箭头的注解
12. def plotNode(nodeTxt, centerPt, parentPt, nodeType) :
13. createPlot.ax1.annotate(nodeTxt, xy = parentPt, xycoords = 'axes fraction', xytext = centerPt, textcoords = 'axes fraction', va = 'center', ha = 'center', bbox = nodeType, arrowprops = arrow_args)
15. def createPlot() :
16. fig = plt.figure(1, facecolor='white')
17. fig.clf()
18. createPlot.ax1 = plt.subplot(111, frameon = False)
19. plotNode(U'决策节点', (0.5, 0.1), (0.1, 0.5), decisionNode)
20. plotNode(U'叶节点', (0.8, 0.1), (0.3, 0.8), leafNode)
21. plt.show()
22. createPlot()

最终得到图像

完成!