提升yfinance API数据获取稳定性：处理异常与无效股票代码的教程

import yfinance as yf

# 假设 0250.HK 存在问题，可能导致后续查询受影响
try:
    yf.Ticker("0250.HK").history(period="max") # 未赋值
except Exception as e:
    print(f"Error fetching 0250.HK: {e}")

# 0001.HK 可能会出现 "No price data found" 警告，即使它是有效的
print(yf.Ticker("0001.HK").history(period="max")) # 未赋值

import yfinance as yf

# 即使是问题股票，也赋值
problematic_data = None
try:
    problematic_data = yf.Ticker("0250.HK").history(period="max")
except Exception as e:
    print(f"Error fetching 0250.HK: {e}")

# 0001.HK 的查询将正常进行，因为之前的操作被正确处理
valid_data = yf.Ticker("0001.HK").history(period="max")
print(valid_data.head()) # 打印数据帧头部

import yfinance as yf
import requests # 用于捕获 HTTPSConnectionPool 相关的异常

tickers = ["0250.HK", "0001.HK", "AAPL"]
all_data = {}

for ticker_symbol in tickers:
    print(f"Fetching data for {ticker_symbol}...")
    try:
        # 尝试获取数据并赋值
        data = yf.Ticker(ticker_symbol).history(period="max")

        # 检查数据帧是否为空，处理 yfinance 警告的情况
        if data.empty:
            print(f"Warning: No historical data found for {ticker_symbol}. It might be delisted or invalid.")
        else:
            all_data[ticker_symbol] = data
            print(f"Successfully fetched data for {ticker_symbol}.")
            # print(data.head()) # 可以选择打印部分数据进行验证

    except requests.exceptions.ConnectionError as e:
        print(f"Connection error for {ticker_symbol}: {e}. Skipping this ticker.")
    except Exception as e:
        print(f"An unexpected error occurred for {ticker_symbol}: {e}. Skipping this ticker.")

print("\n--- Summary of fetched data ---")
for symbol, df in all_data.items():
    print(f"{symbol}: {len(df)} rows of data")

import yfinance as yf

ticker_symbol = "AAPL"
try:
    data = yf.Ticker(ticker_symbol).history(period="max")

    if data.empty:
        print(f"No data found for {ticker_symbol}.")
    else:
        print(f"Data for {ticker_symbol} has {len(data)} rows.")
        # 进一步验证数据，例如检查最新的日期
        if not data.index.empty:
            print(f"Latest date: {data.index.max().strftime('%Y-%m-%d')}")
        else:
            print("Data index is empty.")

except Exception as e:
    print(f"Error fetching {ticker_symbol}: {e}")