I solved my problem...Here is the solution:
import os, re import xlrd def rename_pdfs(): path = r"C:\\Users\\...\\original" excelFile = xlrd.open_workbook(r"C:\\Users\\...\\data.xlsx") workSheet = excelFile.sheet_by_index(0) fileNum = 1 for rownum in range(workSheet.nrows): inv = workSheet.cell_value(5+rownum, 4) for index in re.finditer("1718-", inv): rfr = inv[index.end():index.end() + 10] newFilename = workSheet.cell_value(5+rownum, 1) + " " + "1718-" + rfr os.rename(os.path.join(path, str(fileNum)+".pdf"), os.path.join(r"C:\\Users\\...\\renamed", newFilename+".pdf")) fileNum += 1 if __name__ == "__main__": rename_pdfs()