pytorch项目：测试代码中correct += (y_pred == y).sum().item()

#测试代码中correct += (y_pred == y).sum().item()
import torch
import numpy as np
correct = 0

#case1：当y_pre和y为列表时
y = [1,5,7,8]
y_pred = [2,4,7,9]

correct += (y_pred == y).sum().item() #报错：AttributeError: ‘bool’ object has no attribute ‘sum’

#case2:当y_pre和y为np
y = np.array([3,6,8])
y_pred = np.array([5,6,9])
correct += (y_pred == y).sum().item()
print(correct) # 1

#case3 当为tensor时
y= torch.tensor([5,8,3])
y_pred = torch.tensor([5,8,4])
correct=0
correct += (y_pred == y).sum().item()
print(correct) #2