#範例2-3：繪出藍色虛線(x,y)圖
import matplotlib.pyplot as plt
listx = [1,3,4,6,8,11,13,15,17]
listy = [20,45,30,42,50,60,90,80,100]
plt.plot(listx,listy,color='red',linestyle='--')
#plt.plot(listx,listy,'r--')
plot.show()