dfs = [pd.read_excel(f, sheet_name="Base data",index_col=None,header=0) for f in allFiles]
keys = [os.path.basename(f) for f in allFiles]
frame = pd.concat(dfs, keys=keys)
#if want remove default index values
#frame = pd.concat(dfs, keys=keys).reset_index(level=1, drop=True)