#!/usr/bin/pythonimport timeimport sysdef dateinput():    date = raw_input('please input the first date: ')    return datedef datetrans(tdate):    spdate = tdate.replace("/","-")    try:        datesec = time.strptime(spdate,'%Y-%m-%d')    except ValueError:        print "%s is not a rightful date!!" % tdate        sys.exit(1)    return time.mktime(datesec)def daysdiff(d1,d2):    daysec = 24 * 60 * 60    return int(( d1 - d2 )/daysec)date1 = dateinput()date2 = dateinput()date1sec = datetrans(date1)date2sec = datetrans(date2)print "The number of days between two dates is: ",daysdiff(date1sec,date2sec)