基于 pandas

import os
import xlrdimport numpy as npimport xlrdimport pandas as pd

# df1=pd.read_excel('shuju.xlsx',sheet_name='sheet1')df4=pd.read_excel('Desktop/shuju222.xlsx',sheet_name=3)df5=pd.read_excel('/shuju222.xlsx',sheet_name=4)df3=pd.read_excel('/shuju222.xlsx',sheet_name=2)for i in range(len(df5['年度区间'])):    df5['年度区间'][i] = df5['年度区间'][i].strftime("%Y-%m-%d")result = pd.merge(df5, df4, how='left',on=['年度区间','证券代码'])result1 = pd.merge(result, df3, how='left',on=['年度区间','证券代码'])writer = pd.ExcelWriter('B.xlsx')result.to_excel(writer, 'page_1', float_format='%.5f')writer.save()