PyTorch自定义Dataset报错：'WineDataset'无'x_data'属性

我参考PyTorch教程编写了如下代码：

import torch
import torchvision
from torch.utils.data import Dataset,DataLoader
import numpy as np
import math
class WineDataset(Dataset):
    def __int__(self):
        xy =np.loadtxt("wine.csv",delimiter=',',dtype=np.float32,skiprows=1)
        self.n_samples =xy.shape[0]
        self.x_data = torch.from_numpy(xy[:, 1:])
        self.y_data = torch.from_numpy(xy[:, [0]])
    def __getitem__(self, index):
        return self.x_data[index],self.y_data[index]
    def __len__(self):
        return self.n_samples
# create dataset
dataset = WineDataset()
# get first sample and unpack
first_data = dataset[0]
features, labels = first_data
print(features, labels)

运行时出现以下错误：

Traceback (most recent call last):
  File "C:\Users\User\PycharmProjects\AI_Project\Dataset_DataLoader.py", line 19, in <module>
    first_data = dataset.__getitem__(0)
  File "C:\Users\User\PycharmProjects\AI_Project\Dataset_DataLoader.py", line 13, in __getitem__
    return self.x_data[index],self.y_data[index]
AttributeError: 'WineDataset' object has no attribute 'x_data'

请问错误出在哪里？

错误根源是类的构造函数名称写错了：你把Python构造函数__init__误写成了__int__，导致类实例化时完全没有执行初始化逻辑，self.x_data、self.y_data这些属性从未被创建，因此调用__getitem__时会触发属性不存在的错误。

只需把构造函数名称修正为__init__即可解决问题，修正后的代码如下：

import torch
import torchvision
from torch.utils.data import Dataset,DataLoader
import numpy as np
import math
class WineDataset(Dataset):
    # 修正构造函数名称
    def __init__(self):
        xy =np.loadtxt("wine.csv",delimiter=',',dtype=np.float32,skiprows=1)
        self.n_samples =xy.shape[0]
        self.x_data = torch.from_numpy(xy[:, 1:])
        self.y_data = torch.from_numpy(xy[:, [0]])
    def __getitem__(self, index):
        return self.x_data[index],self.y_data[index]
    def __len__(self):
        return self.n_samples
# create dataset
dataset = WineDataset()
# get first sample and unpack
first_data = dataset[0]
features, labels = first_data
print(features, labels)

修改后，实例化WineDataset时构造函数会正常执行，初始化所需的属性，后续调用__getitem__就不会再报错。

内容的提问来源于stack exchange，提问作者user466534