如何在numpy数组中存储不同大小的arraylist（用于聚类）？

 a=[]
 for (x,y,w,h) in faces:
    for (ex,ey,ew,eh) in eyes:
               cv2.rectangle(roi_color,(ex,ey),(ex+ew,ey+eh),(0,255,0),2)
               a.append(eyes)        
               i+=1
 print(a)
 a=[]
 for (x,y,w,h) in faces:
    for (ex,ey,e