matplotlib如何写出汉字

from matplotlib.font_manager import FontProperties  
import numpy as np
import matplotlib.pyplot as plt  
font = FontProperties(fname="/usr/share/fonts/truetype/droid/DroidSansFallbackFull.ttf", size=14)  
plt.figure(figsize=(5,5))
x=np.arange(0,5,0.1)
y=np.sin(x)
plt.plot(x,y,color='r',label='sin')
plt.legend(loc=1)
plt.xlabel(u"横坐标", fontproperties=font)  
plt.ylabel(u"纵坐标", fontproperties=font)  
plt.title(u"正弦函数",fontproperties=font)  
plt.text(0.5,0.5,u'正弦函数',fontproperties=font)