# -*- coding: utf-8 -*-‘‘‘获取当前日期前后N天或N月的日期‘‘‘from time import strftime, localtimefrom datetime import timedelta, dateimport calendaryear = strftime("%Y",localtime())mon  = strftime("%m",localtime())day  = strftime("%d",localtime())hour = strftime("%H",localtime())min  = strftime("%M",localtime())sec  = strftime("%S",localtime())def today():    ‘‘‘‘‘    get today,date format="YYYY-MM-DD"    ‘‘‘‘‘    return date.today()def todaystr():    ‘‘‘    get date string, date format="YYYYMMDD"    ‘‘‘    return year+mon+daydef datetime():    ‘‘‘‘‘    get datetime,format="YYYY-MM-DD HH:MM:SS"    ‘‘‘    return strftime("%Y-%m-%d %H:%M:%S",localtime())def datetimestr():    ‘‘‘‘‘    get datetime string    date format="YYYYMMDDHHMMSS"    ‘‘‘    return year+mon+day+hour+min+secdef get_day_of_day(n=0):    ‘‘‘‘‘    if n>=0,date is larger than today    if n<0,date is less than today    date format = "YYYY-MM-DD"    ‘‘‘    if(n<0):        n = abs(n)        return date.today()-timedelta(days=n)    else:        return date.today()+timedelta(days=n)def get_days_of_month(year,mon):     ‘‘‘‘‘     get days of month     ‘‘‘     return calendar.monthrange(year, mon)[1]   def get_firstday_of_month(year,mon):     ‘‘‘‘‘     get the first day of month     date format = "YYYY-MM-DD"     ‘‘‘     days="01"     if(int(mon)<10):         mon = "0"+str(int(mon))     arr = (year,mon,days)     return "-".join("%s" %i for i in arr)   def get_lastday_of_month(year,mon):     ‘‘‘‘‘     get the last day of month     date format = "YYYY-MM-DD"     ‘‘‘     days=calendar.monthrange(year, mon)[1]     mon = addzero(mon)     arr = (year,mon,days)     return "-".join("%s" %i for i in arr)   def get_firstday_month(n=0):     ‘‘‘‘‘     get the first day of month from today     n is how many months     ‘‘‘     (y,m,d) = getyearandmonth(n)     d = "01"     arr = (y,m,d)     return "-".join("%s" %i for i in arr)   def get_lastday_month(n=0):     ‘‘‘‘‘     get the last day of month from today     n is how many months     ‘‘‘     return "-".join("%s" %i for i in getyearandmonth(n))  def getyearandmonth(n=0):     ‘‘‘‘‘     get the year,month,days from today     befor or after n months     ‘‘‘     thisyear = int(year)     thismon = int(mon)     totalmon = thismon+n     if(n>=0):         if(totalmon<=12):             days = str(get_days_of_month(thisyear,totalmon))             totalmon = addzero(totalmon)             return (year,totalmon,days)         else:             i = totalmon/12             j = totalmon%12             if(j==0):                 i-=1                 j=12             thisyear += i             days = str(get_days_of_month(thisyear,j))             j = addzero(j)             return (str(thisyear),str(j),days)     else:         if((totalmon>0) and (totalmon<12)):             days = str(get_days_of_month(thisyear,totalmon))             totalmon = addzero(totalmon)             return (year,totalmon,days)         else:             i = totalmon/12             j = totalmon%12             if(j==0):                 i-=1                 j=12             thisyear +=i             days = str(get_days_of_month(thisyear,j))             j = addzero(j)             return (str(thisyear),str(j),days)   def addzero(n):     ‘‘‘‘‘     add 0 before 0-9     return 01-09     ‘‘‘     nabs = abs(int(n))     if(nabs<10):         return "0"+str(nabs)     else:         return nabs def get_today_month(n=0):     ‘‘‘‘‘     获取当前日期前后N月的日期    if n>0, 获取当前日期前N月的日期    if n<0, 获取当前日期后N月的日期    date format = "YYYY-MM-DD"     ‘‘‘     (y,m,d) = getyearandmonth(n)     arr=(y,m,d)     if(int(day)<int(d)):         arr = (y,m,day)     return "-".join("%s" %i for i in arr)   if __name__=="__main__":    print today()      print todaystr()    print datetime()    print datetimestr()    print get_day_of_day(20)    print get_day_of_day(-3)    print get_today_month(-3)    print get_today_month(3)