python 日期操作类代码

# -*- 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)