python - 迭代 python 嵌套列表

Question

我需要将列表 'a' 转换为列表 'b' ， 怎么做？

a = [[[1, 2, 3], [4, 5, 6]], [[7, 8, 9], [10, 11, 12,]]]

b = [[[1, 2, 3, 4, 5, 6]], [[7, 8, 9, 10, 11, 12,]]]

Answer 1

我建议以下列表理解:

In [1]: a = [[[1, 2, 3], [4, 5, 6]], [[7, 8, 9], [10, 11, 12,]]]
   ...:

In [2]: [[[a for sub in nested for a in sub]] for nested in a]
Out[2]: [[[1, 2, 3, 4, 5, 6]], [[7, 8, 9, 10, 11, 12]]]

它等价于下面的嵌套for循环:

result = []
for nested in a:
    _temp = []
    for sub in nested:
        for a in sub:
            _temp.append(a)
    result.append([_temp])

不过，我更愿意这样写:

result = []
for nested in a:
    _temp = []
    for sub in nested:
        _temp.extend(sub)
    result.append([_temp])