1、以torch的切片为例
import torch
a = torch.arange(20).reshape(4, 5)
print(a)
print(a[..., 0])
print(a[..., 1])
print(a[..., 2])
b = torch.arange(20).reshape(2, 2, 5)
print(b)
print(b[..., 0])
print(b[..., 1])
print(b[..., 2])
2、输出如下:
# a
tensor([[ 0, 1, 2, 3, 4],
[ 5, 6, 7, 8, 9],
[10, 11, 12, 13, 14],
[15, 16, 17, 18, 19]])
# a[..., 0]
tensor([ 0, 5, 10, 15])
# a[..., 1]
tensor([ 1, 6, 11, 16])
# a[..., 2]
tensor([ 2, 7, 12, 17])
# b
tensor([[[ 0, 1, 2, 3, 4],
[ 5, 6, 7, 8, 9]],
[[10, 11, 12, 13, 14],
[15, 16, 17, 18, 19]]])
# b[..., 0]
tensor([[ 0, 5],
[10, 15]])
# b[..., 1]
tensor([[ 1, 6],
[11, 16]])
# b[..., 2]
tensor([[ 2, 7],
[12, 17]])
结论:…是省略号的意思,忽略掉省略号所表示所有的维度,后面的数字表示取该维度的指定列