import os
import pandas as pd

filelist = ['your/path/tofile1', 'your/path/tofile2', 'your/path/tofile3', etc]
filedate = 0
for file in fileslist:
    if os.path.getmtime(file) > filedate:
        newestfile, filedate = file, os.path.getmtime(file)
pd.read_excel(newestfile)