Python代码横着写是很有美感的

def all_images(ial):
'''Return a list of all the images in image association list "ial".
Exclude duplicates.
'''
l = []
for s in ial:
l += s [1]
l.sort ()
end = l[-1]
for i in range (len(l)-2, -1, -1 ):
if end == l[i] : del[i]
else:
end = l[i]
return l



测试一直不过：
Result for [['a', [1, 2, 3]], ['b', [5, 6, 3]]]
should be [1, 2, 3, 5, 6]
not [1, 2, 3, 3, 5, 6]