完整报错：
RuntimeError: stack expects each tensor to be equal size, but got [4] at entry 0 and [3] at entry 30

问题所在：
使用pytorch的DataSet类中的getitem方法切分数据时，最后一个数据切分不完整。

解决办法：
重写len方法，把数据集返回长度处理一下即可，避免有不完整的数据留下

from torch.utils.data import Dataset  

  
class MyDataset(Dataset):  
    def __init__(self,data,days_for_train): 
        self.data = data
        self.days_for_train = days_for_train
        self.label_len = 0
        self.pred_len = 1
  
    def __len__(self):  
        # 返回数据集的大小  
        return len(self.data) - self.days_for_train + 1
  

    
    def __getitem__(self, index):
        s_begin = index
        s_end = s_begin + self.days_for_train
        r_begin = s_end
        r_end = r_begin + self.pred_len

        seq_x = self.data[s_begin:s_end]
        seq_y = self.data[r_begin:r_end]


        return seq_x, seq_y