为什么代码在 Python 中途停止运行

Question

这是我用于抓取一些财务数据的 Python 示例

---

import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
from matplotlib import dates as mdates
import datetime as dt
from mplfinance.original_flavor import candlestick_ohlc
import warnings
warnings.filterwarnings("ignore")

# fix_yahoo_finance is used to fetch data 
import yfinance as yf
yf.pdr_override()

# input
symbol = 'AAPL'
start = '2018-01-01'
end = '2020-12-24'

# Read data 
df = yf.download(symbol,start,end)

# View Columns
df.head()
df['Absolute_Return'] = 100 * (df['Adj Close'] - df['Adj Close'].shift(1))/df['Adj Close'].shift(1)
df.head(20)
fig = plt.figure(figsize=(14,10))
ax1 = plt.subplot(2, 1, 1)
ax1.plot(df['Adj Close'])
ax1.set_title('Stock '+ symbol +' Closing Price')
ax1.set_ylabel('Price')

ax2 = plt.subplot(2, 1, 2)
ax2.plot(df['Absolute_Return'] , label='Absolute Return', color='red')
#ax2.axhline(y=0, color='blue', linestyle='--')
#ax2.axhline(y=0.5, color='darkblue')
#ax2.axhline(y=-0.5, color='darkblue')
ax2.grid()
ax2.set_ylabel('Absolute Return')
ax2.set_xlabel('Date')
ax2.legend(loc='best')

问题是，如果我将它们放在 Jupyter notebook 中并逐块运行，则一切正常。但是当我把它们放在一个普通的 .py 文件中然后运行它时，它中途停止，就在

df = yf.download(symbol,start,end)

有人帮我解释一下吗？