python 中 list，numpy，tensor的互相轉換

import torch
import numpy as np


print('##########建立 a-list;; b-numpy;; c- tensor##########')
a = [1,2,3,4,5]
b = np.array([1,2,3,4,5])
c = torch.arange(1,6)
print('a-list:',a,'\n',
      'b-ndarray:',b,'\n',
      'c-tensor:',c,c.type())

print('\n########list轉numpy  和  tensor  ###############')
list_numpy = np.array(a)
list_tensor = torch.tensor(a)
print(list_numpy,list_tensor)

print('\n##########numpy轉 list  和  tensor  ##########')
numpy_list = b.tolist()
numpy_tensor = torch.from_numpy(b)
print(numpy_list,numpy_tensor)

print('\n##############tensor 轉 list (先轉numpy，後轉list)  和  numpy  ##########')
tensor_list = c.numpy().tolist()
tensor_numpy = c.numpy()
print(tensor_list,tensor_numpy)

# 如果tensor是GPU上的tensor，先轉成CPU，再轉爲numpy
ndarray = tensor.cpu().numpy()

#輸出#

E:\Anconda\python.exe "C:/Users/MR-LI/Desktop/program practice/TRY/train.py"
##########建立 a-list;; b-numpy;; c- tensor##########
a-list: [1, 2, 3, 4, 5] 
 b-ndarray: [1 2 3 4 5] 
 c-tensor: tensor([1, 2, 3, 4, 5]) torch.LongTensor

########list轉numpy  和  tensor  ###############
[1 2 3 4 5] tensor([1, 2, 3, 4, 5])

##########numpy轉 list  和  tensor  ##########
[1, 2, 3, 4, 5] tensor([1, 2, 3, 4, 5], dtype=torch.int32)

##############tensor 轉 list  和  numpy  ##########
[1, 2, 3, 4, 5] [1 2 3 4 5]