readNum = "+CNUM ,:4915128040906:,129" firstQuote = readNum.find(':') cutString = readNum [firstQuote:] print cutString secondQuote = cutString.find(',') number = cutString[1:secondQuote-1] print number print number[0:1] if number.find('+') == 0: number = '0'+number[3:len(number)] elif int(number[0:1]) == 4: number = '0'+number[2:len(number)] print number