import pandas as pd merged_df = pd.read_csv('data/afghan_wheatfcasts.csv', parse_dates = ['Date']) df_backtest_ = pd.read_csv('data/aghanwheat_allhistorical.csv', parse_dates=['Date']) # df_backtest_.rename(columns={'date':"Date"},inplace=True) final_wheat = pd.merge(df_backtest_,merged_df,on=['Date'],how='outer') final_wheat.to_csv('data/final_afgh_wheat.csv',index=False)