import numpy as np
import matplotlib.pyplot as plt

x= [1,2,3,4,5,6,7,8]                                #[1]X坐标点
y= [2,3,4,6,2,3,8,6]

plt.figure()
plt.subplot()
data       = np.array([[3,3,3,15,3,3,3,10],         #[1]蓝色y坐标值
                       [2,6,2,3,2,9,14,2],          #[2]红色y坐标值
                       [4,3,9,4,12,4,21,4],         #[3]绿色y坐标值
                       [4,14,6,13,4,4,21,4]])       #[4]灰色y坐标值
index      = np.arange(data.shape[1])
color_index= ['r','g','b','y']

for i in range(4):
    j = i+1
    #index+2:是起始坐标点    #width是bar的宽度
    plt.bar(index+2,data[i],width=0.7,color=color_index[i],bottom=np.sum(data[:i],axis=0))

plt.show()