解决：

问题描述：

原代码如下:

import pandas as pdfrom statsmodels.tsa.stattools import adfullerimport torch
import torch.nn as nn
import torch.optim as optim
import torch.nn.functional as Ffrom blitz.modules import BayesianLSTM
from blitz.utils import variational_estimatorfrom sklearn.model_selection import train_test_split
from sklearn.preprocessing import StandardScaler
from sklearn.linear_model import LinearRegressionimport matplotlib.pyplot as plt
%matplotlib inlinefrom collections import dequeimport yfinance as yf
import numpy as npplt.rcParams.update({'figure.figsize':(20,10)})
plt.rcParams.update({'font.size':20})

ticker = "SPY" 
ticker_y = yf.Ticker("SPY")
df = ticker_y.history(period="5y")

然后出现报错：- SPY: No data found for this date range, symbol may be delisted

- SPY: No data found for this date range, symbol may be delisted

解决方案：

其实原因就在于这里使用的为Yahoo财经数据（从import yfinance as yf就可以证明这是Yahoo财经数据），但是由于现在使用Python访问不了那个网站了，所以可以自行寻找该网站的数据。使用read_csv等函数进行引用。
因此，解决方案为：

import pandas as pdfrom statsmodels.tsa.stattools import adfullerimport torch
import torch.nn as nn
import torch.optim as optim
import torch.nn.functional as Ffrom blitz.modules import BayesianLSTM
from blitz.utils import variational_estimatorfrom sklearn.model_selection import train_test_split
from sklearn.preprocessing import StandardScaler
from sklearn.linear_model import LinearRegressionimport matplotlib.pyplot as plt
%matplotlib inlinefrom collections import dequeimport yfinance as yf
import numpy as npplt.rcParams.update({'figure.figsize':(20,10)})
plt.rcParams.update({'font.size':20})

df_non_stat = pd.read_csv("stock_train.csv", index_col = 0, parse_dates=[0])
df_non_stat

输出结果：

如果想要测试代码，自己可以按照上述字段来，这就是使用的格式了