python时间处理

import time;
import os;
import sys;

#print a day
def PrintTime(stTime):
    print("%s-%s-%s %s:%s:%s" %(stTime.tm_year, stTime.tm_mon, stTime.tm_mday, stTime.tm_hour, stTime.tm_min, stTime.tm_sec));

def ToInt(strVal):
    try:
        nVal = int(strVal);
    except:
        return 0;
    return nVal;


def GetNextDay(nDay):
    print("----------Next %s Day --------------" %nDay);
    nTimes = time.time() + (ToInt(nDay) * 60 * 60 * 24);
    PrintTime(time.localtime(nTimes));
    
def DoNextDay():
    nDays = input("please input days:");
    GetNextDay(nDays);

def DoGetDays():
    strDate1 = input("please input first date:");
    strDate2 = input("please input second date:");
    
    stDate1 = time.strptime(strDate1, '%Y-%m-%d');
    stDate2 = time.strptime(strDate2, '%Y-%m-%d');

    nSec1 = time.mktime(stDate1) - (stDate1.tm_hour * 60 * 60 + stDate1.tm_min * 60 + stDate1.tm_sec);
    nSec2 = time.mktime(stDate2) - (stDate2.tm_hour * 60 * 60 + stDate2.tm_min * 60 + stDate2.tm_sec);

    nDay = ToInt((nSec2 - nSec1) / (24 * 60 * 60));
    print("相差:%s天" %nDay);

def PrintMessage():
    print("------------------------------------------");
    print("0. 计算N天之后的日期");
    print("1. 计算2个日期直接的间隔日");
    print("exit 退出");
    print("------------------------------------------");

if "__main__" == __name__:
    while 1:
        print("---------Current Day -----------");
        PrintTime(time.localtime(time.time()));

        PrintMessage();
        strInput = input("请选择:");
        if "exit" == strInput:
            sys.exit(0);
        elif '0' == strInput:
            DoNextDay();            
        elif '1' == strInput:
            DoGetDays();
        else:
            print("请输入正确的命令");

        print("\n\n");