计算多月/多日前后 日期

from time import strftime, localtime
from datetime import timedelta, date
import calendar

  def _get_days_of_month(self, year, mon):
        """
        get days of month
        """
        # print calendar.monthrange(year, mon)[1]
        return calendar.monthrange(year, mon)[1]

    def _addzero(self, n):
        """
        add 0 before 0-9
        return 01-09
        """
        nabs = abs(int(n))
        if nabs < 10:
            return "0" + str(nabs)
        else:
            return nabs

    def _getyearandmonth(self, n=0):
        """
        get the month,days,year from today
        before or after n months
        """

        thisyear = int(self.year)
        thismon = int(self.mon)
        totalmon = thismon + n
        if n >= 0:
            if totalmon <= 12:
                days = str(self._get_days_of_month(thisyear, totalmon))
                totalmon = self._addzero(totalmon)
                return self.year, totalmon, days
            else:
                i = totalmon / 12
                j = totalmon % 12
                if j == 0:
                    i -= 1
                    j = 12
                thisyear += i
                days = str(self._get_days_of_month(thisyear, j))
                j = self._addzero(j)
                return str(thisyear), str(j), days
        else:
            if (totalmon > 0) and (totalmon < 12):
                days = str(self._get_days_of_month(thisyear, totalmon))
                totalmon = self._addzero(totalmon)
                return self.year, totalmon, days
            else:
                i = totalmon / 12
                j = totalmon % 12
                if j == 0:
                    i -= 1
                    j = 12
                thisyear += i
                days = str(self._get_days_of_month(thisyear, j))
                j = self._addzero(j)
                return str(thisyear), str(j), days

    def _get_today_month(self, n=0):
        (y, m, d) = self._getyearandmonth(n)
        arr = (y, m, d)
        if int(self.day) < int(d):
            arr = (y, m, self.day)
        return "/".join("%s" % i for i in arr)

    def _get_day_of_day(self, n=0):
        """
        if n>=0,date is larger than today
        if n<0,date is less than today
        date format = "YYYY-MM-DD"
        """
        return date.today() + timedelta(days=n)

    def _get_access_info(self):
        username = self.session.selenium2.find_element_by_id('username_set').text
        passphrase = self.session.selenium2.find_element_by_id('passphrase_set').text
        expiration = self.session.selenium2.find_element_by_id('expiration_set').text
        self.session.sleep(1)
        self.session.selenium2.click('css', 'button.wgrd-modal-save:nth-child(1)')
        return username, passphrase, expiration

    def _get_exp_time(self):
        if self.expiration.strip() == 'None':
            exp_time = 'Never'
        elif self.expiration.strip() == '3 months':
            exp_time = self._get_today_month(3)
        elif self.expiration.strip() == '1 month':
            exp_time = self._get_today_month(1)
        elif self.expiration.strip() == '1 week':
            exp_time = str(self._get_day_of_day(7)).replace('-', '/')
        else:
            exp_time = str(self._get_day_of_day(1)).replace('-', '/')
        return exp_time

    def _check_access_info(self, usr, pas, exp):
        exp_time = self._get_exp_time()
        print exp_time
        if exp_time != 'Never':
            day = exp.strip().split(' ')[0].split('/')[1]
            month = exp.strip().split(' ')[0].split('/')[0]
            year = exp.strip().split(' ')[0].split('/')[2]
            day = self._addzero(day)
            month = self._addzero(month)
            exp = str(year) + '/' + str(month) + '/' + str(day)
            if self.automatic_credentials == 'no':
                print 'exp:', exp
                if usr == self.user_name and pas == self.passphrase and exp == exp_time:

                    self.session.log.info('Enable Support Access successfully, '
                                          'username: %s passphrase: %s expiration: %s' % (usr, pas, exp))
                else:
                    self.session.log.warning('Some information are wrong, please check.')
            else:
                if exp == exp_time:
                    self.session.log.info('Enable Support Access successfully, expiration: %s' % exp)
                else:
                    self.session.log.warning('Some information are wrong, please check.')
        else:
            if self.automatic_credentials == 'no':
                if usr == self.user_name and pas == self.passphrase and exp == 'Never':
                    self.session.log.info('Enable Support Access successfully, '
                                          'username: %s passphrase: %s expiration: %s' % (usr, pas, exp))
                else:
                    self.session.log.warning('Some information are wrong, please check.')
            else:
                if exp == 'Never':
                    self.session.log.info('Enable Support Access successfully, expiration: %s' % exp)
                else:
                    self.session.log.warning('Some information are wrong, please check.')