import pandas as pd
import os

cache_file = "market_data_cache.pkl"
if os.path.exists(cache_file):
    df = pd.read_pickle(cache_file)
    print("Columns structure type:", type(df.columns))
    if isinstance(df.columns, pd.MultiIndex):
        close = df["Close"]
    else:
        close = df
    print("Start date in cache:", close.index[0])
    print("End date in cache:", close.index[-1])
    print("Number of columns:", len(close.columns))
else:
    print("Cache file not found!")