fix typing error in stocks.py

stocks.py

@@ -7,7 +7,7 @@ import pandas as pd
 class StockMarketAnalyzer:
     def __init__(
         self,
-        market_data: dict[str, pd.DataFrame],
+        market_data: Dict[str, pd.DataFrame],
         sector: str = "NASDAQ",
         date_col: str = "Date",
         price_col: str = "Open",
@@ -69,7 +69,7 @@ class StockMarketAnalyzer:
         return stock_ratio > sector_ratio
 
 
-def load_stock_prices(files: Iterable[Path]) -> dict[str, pd.DataFrame]:
+def load_stock_prices(files: Iterable[Path]) -> Dict[str, pd.DataFrame]:
     """
     Load stock prices from CSV files into a dictionary of DataFrames.
 
@@ -78,7 +78,7 @@ def load_stock_prices(files: Iterable[Path]) -> dict[str, pd.DataFrame]:
         CSV files to load.
 
     Returns:
-        dict[str, pd.DataFrame]: A dictionary where the keys are the company names
+        Dict[str, pd.DataFrame]: A dictionary where the keys are the company names
         (extracted from the file names) and the values are pandas DataFrames
         containing the stock prices for each company.
     """