Windows Forms: событие SelectionChanged для класса TextBox

demand_scenarios = {'low': low_demand_df, 'medium_low': med_low_demand_df, 'medium': bc_demand_df, 'medium_high': med_high_demand_df, 'high': high_demand_df}
dates = pd.date_range(start='2020-10-01', end='2070-09-30', freq='D')

demand_dict = {}
    for key, df in demand_scenarios.items():
        df.index = pd.to_datetime([df].index, format='%Y')
        df = df.tshift(-92, 'D')
        df = df.resample('D').ffill()
        df = df.reindex(dates)
        demand_dict[key] = df

items() вернуть ключ словаря и значение