查看张量形状len(?)、shape、.numel()以及.reshape()

import torch

a = torch.randn(2, 2)
print(a)
print(a.shape)          #张量的形状 （沿每个轴的长度）
print(len(a))           
print(a.numel())        #张量中元素的总数

 reshape(x,y,z)

import torch

b=torch.arange(12)
print(b)
print("----")
print(b.reshape(3,4))
print(b.reshape(-1,4))
print(b.reshape(3,-1))

print(b.reshape(2,2,3)) 
print(b.reshape(2,2,-1))    #

print(b.reshape(2,3,2))  #大空行分开2行，每行中有三行，有2列