python 组合问题出现的错误

2013-01-07 12:17:58 139 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

别再死记硬背了！用Python的combinations函数玩转组合问题（附5个实战场景）本文详细解析了Python中`itertools.combinations`函数的5大实战应用场景，涵盖数据分析、算法优化、游戏开发等领域。通过具体代码示例展示如何高效解决组合问题，如用户分群、特征组合、卡牌游戏设计等，帮助开发者提升代码效率与质量。掌握这一函数可显著简化组合问题的处理流程。阅读详情

我想要写一个函数能通过顶点和长宽高找到一个长方体八个顶点的坐标。
# x, y, z
v = ['x', 'y', 'z']

# length width height
th = ['L','W','H']

vertex = [None]*3

def ver(i):
if i <0 and vertex != []:
print vertex
else:
for x in ['+','-']:
t = v[i] + x + th[i] + ‘/2’
vertex[i] = t
ver(i-1)
['x+L/2', 'y+W/2', 'z+H/2']
['x-L/2', 'y+W/2', 'z+H/2']
['x+L/2', 'y-W/2', 'z+H/2']
['x-L/2', 'y-W/2', 'z+H/2']
['x+L/2', 'y+W/2', 'z-H/2']
['x-L/2', 'y+W/2', 'z-H/2']
['x+L/2', 'y-W/2', 'z-H/2']
['x-L/2', 'y-W/2', 'z-H/2']

就像是八皇后那样的方法，但是当我想把他们结果保存起来，而不是打印时，就不对了。

# x, y, z
v = ['x', 'y', 'z']

# length width height
th = ['L','W','H']

vertex = [None]*3

res = []
def ver(i):
if i <0 and vertex != []:
res.append(vertex)
else:
for x in ['+','-']:
t = v[i] + x + th[i]+'/2'
vertex[i] = t
ver(i-1)

ver(2)

print res
现在的res全都是['x-L/2', 'y-W/2', 'z-H/2']
[['x-L/2', 'y-W/2', 'z-H/2'], ['x-L/2', 'y-W/2', 'z-H/2'], ['x-L/2', 'y-W/2', 'z-H/2'], ['x-L/2', 'y-W/2', 'z-H/2'], ['x-L/2', 'y-W/2', 'z-H/2'], ['x-L/2', 'y-W/2', 'z-H/2'], ['x-L/2', 'y-W/2', 'z-H/2'], ['x-L/2', 'y-W/2', 'z-H/2']]

请问是为什么？

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