Question

我想准备包含所有可能参数组合的列表列表，这些组合将用于强力搜索。参数组合应如下所示：

[0,0,1]
[0,0.2,0.8]
[0.2,0,0.8]
...
[0.4,0.4,0.2]
...
[1,0,0]

生成这些列表的代码工作正常 - 在每次迭代中打印 weights_temp 都会返回正确的结果。但是附加有一些问题。当我打印权重时，我得到的就是这个（最后 weights_temp 值而不是其他元素）：

[1.0,0.0,0.0]
[1.0,0.0,0.0]
...
[1.0,0.0,0.0]
...
[1.0,0.0,0.0]

这是我的代码：

step = 0.2

weights_temp = [0, 0, 1]
weights = [weights_temp]

i = 1

while weights_temp != [1, 0, 0]:
    # decrease gamma
    weights_temp[2] = 1 - i * step

    for j in xrange(0, i + 1):
        # increase alpha, decrease beta
        weights_temp[0] = j * step
        weights_temp[1] = abs(1 - weights_temp[2]) - j * step

        weights.append(weights_temp)

        print weights_temp

    i += 1

有人知道如何解决这个问题吗？

提前谢谢

Answer 1

继续我的评论，而不是添加引用，每次添加列表理解时都会创建一个新列表。

weights.append([item for item in weights_temp])

示例：

>>> temp = [1,2,3]
>>> holder = [temp]
>>> holder
[[1, 2, 3]]
>>> temp[0] += 1
>>> holder
[[2, 2, 3]]
>>> holder.append([item for item in temp])
>>> holder
[[2, 2, 3], [2, 2, 3]]
>>> temp[0] +=1
>>> holder
[[3, 2, 3], [2, 2, 3]]

Answer 2

for s in arr:
li.append(
    {"id":s.get("InstanceId"),"Message":s.get("Status").get("Message") }
 )

Append用最后一个附加值覆盖每个元素（Python）

2 个答案: