访问嵌套列表中的元素 [英] Accessing elements in a nested list

问题描述

我在嵌套列表中有一个名为"train_data"的元素，如示例所示:

I have elements in a nested list called "train_data" like in the example:

[0] [0.935897, 1.0, 1.0, 0.928772, 0.053629, 0.0, 39.559883, 0.009494, 0]
[1] [0.467681, 1.0, 1.0, 0.778987, 0.069336, 0.0, 56.571999, 0.024675, 0]
[2] [0.393258, 1.0, 1.0, 0.843201, 0.068779, 0.0, 66.866669, 0.069206, 1]

我想访问前8列的所有行(除了最后一列)，以及仅最后一列的所有行.我需要在一行代码中没有for循环.

I would like to access all rows with the first 8 columns (all but the last one), and all rows with only the last column. I need to this without for loops, in a single line of code.

我尝试过这样的事情:

print train_data[0][:]
print train_data[:][0]

但这给了我相同的结果:

but this gives me the same result:

[0.935897, 1.0, 1.0, 0.928772, 0.053629, 0.0, 39.559883, 0.009494, 0]
[0.935897, 1.0, 1.0, 0.928772, 0.053629, 0.0, 39.559883, 0.009494, 0]

有人可以帮我吗?

对不起，第一个查询的预期输出是:

Sorry, the expected output for the first query is:

[0.935897, 1.0, 1.0, 0.928772, 0.053629, 0.0, 39.559883, 0.009494]
[0.467681, 1.0, 1.0, 0.778987, 0.069336, 0.0, 56.571999, 0.024675]
[0.393258, 1.0, 1.0, 0.843201, 0.068779, 0.0, 66.866669, 0.069206]

，第二个查询是:

[0]
[0]
[1]

推荐答案

我认为您正在期待

L1 = [x[0:-1] for x in train_data]
L2 = [x[-1] for x in train_data]

for x in L1:
    print x

for x in L2:
    print [x]

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