odoo开发笔记-日期时间相关操作

日期格式化字符串：DATE_FORMAT = "%Y-%m-%d"

日期时间格式字符串：DATETIME_FORMAT = "%Y-%m-%d %H:%M:%S"

日期时间格式字符串（包含毫秒）：DATETIME_FORMAT = "%Y-%m-%d %H:%M:%S.%f"

OpenERP对象中字段赋值为当前日期（字符串）：fields.date.context_today，fields.date.context_today(self, cr, uid, context=context)，fields.date.today()

OpenERP对象中字段赋值为当前时间（字符串）：fields.datetime.now()，fields.datetime.context_timestamp(cr, uid, datetime.now(), context=context)

OpenERP官方建议 date/datetime 的默认值的写法是：fields.date.context_today，fields.datetime.now()

字符串转换为日期时间：datetime.datetime.strptime(sale.date, DATE_FORMAT)

日期时间转换为字符串：datetime.datetime.strftime(datetime.date.today(), DATE_FORMAT)

python中获取当前日期：datetime.date.today()

python中获取当前时间：datetime.datetime.now()

OpenERP fields 单元中对 date/datetime 类中方法定义如下所示：

class date(_column):
    _type = 'date'

    @staticmethod
    def today(*args):
        """ Returns the current date in a format fit for being a
        default value to a ``date`` field.

        This method should be provided as is to the _defaults dict, it
        should not be called.
        """
        return DT.date.today().strftime(
            tools.DEFAULT_SERVER_DATE_FORMAT)

    @staticmethod
    def context_today(model, cr, uid, context=None, timestamp=None):
        """Returns the current date as seen in the client's timezone
           in a format fit for date fields.
           This method may be passed as value to initialize _defaults.

           :param Model model: model (osv) for which the date value is being
                               computed - automatically passed when used in
                                _defaults.
           :param datetime timestamp: optional datetime value to use instead of
                                      the current date and time (must be a
                                      datetime, regular dates can't be converted
                                      between timezones.)
           :param dict context: the 'tz' key in the context should give the
                                name of the User/Client timezone (otherwise
                                UTC is used)
           :rtype: str 
        """
        today = timestamp or DT.datetime.now()
        context_today = None
        if context and context.get('tz'):
            tz_name = context['tz']  
        else:
            tz_name = model.pool.get('res.users').read(cr, SUPERUSER_ID, uid, ['tz'])['tz']
        if tz_name:
            try:
                utc = pytz.timezone('UTC')
                context_tz = pytz.timezone(tz_name)
                utc_today = utc.localize(today, is_dst=False) # UTC = no DST
                context_today = utc_today.astimezone(context_tz)
            except Exception:
                _logger.debug("failed to compute context/client-specific today date, "
                              "using the UTC value for `today`",
                              exc_info=True)
        return (context_today or today).strftime(tools.DEFAULT_SERVER_DATE_FORMAT)

class datetime(_column):
    _type = 'datetime'
    @staticmethod
    def now(*args):
        """ Returns the current datetime in a format fit for being a
        default value to a ``datetime`` field.

        This method should be provided as is to the _defaults dict, it
        should not be called.
        """
        return DT.datetime.now().strftime(
            tools.DEFAULT_SERVER_DATETIME_FORMAT)

    @staticmethod
    def context_timestamp(cr, uid, timestamp, context=None):
        """Returns the given timestamp converted to the client's timezone.
           This method is *not* meant for use as a _defaults initializer,
           because datetime fields are automatically converted upon
           display on client side. For _defaults you :meth:`fields.datetime.now`
           should be used instead.

           :param datetime timestamp: naive datetime value (expressed in UTC)
                                      to be converted to the client timezone
           :param dict context: the 'tz' key in the context should give the
                                name of the User/Client timezone (otherwise
                                UTC is used)
           :rtype: datetime
           :return: timestamp converted to timezone-aware datetime in context
                    timezone
        """
        assert isinstance(timestamp, DT.datetime), 'Datetime instance expected'
        if context and context.get('tz'):
            tz_name = context['tz']  
        else:
            registry = openerp.modules.registry.RegistryManager.get(cr.dbname)
            tz_name = registry.get('res.users').read(cr, SUPERUSER_ID, uid, ['tz'])['tz']
        if tz_name:
            try:
                utc = pytz.timezone('UTC')
                context_tz = pytz.timezone(tz_name)
                utc_timestamp = utc.localize(timestamp, is_dst=False) # UTC = no DST
                return utc_timestamp.astimezone(context_tz)
            except Exception:
                _logger.debug("failed to compute context/client-specific timestamp, "
                              "using the UTC value",
                              exc_info=True)
        return timestamp

应用示例代码： 

    #自动获取日期对应的月份并保存

    def _get_month(self, cr, uid, ids, field_name, arg, context=None):
        res = {}
        if context is None:
            context = {}
        DATETIME_FORMAT = "%Y-%m-%d"
        for sale in self.browse(cr, uid, ids, context=context):
            saledate = datetime.datetime.strptime(sale.date, DATETIME_FORMAT)
            res[sale.id] = saledate.strftime('%Y') + '-' + saledate.strftime('%m')
        return res
    
    _columns={
        'name':fields.char(u'单号', size=64, select=True, required=True, readonly=True),
        'date':fields.date(u'日期', select=True, required=True, readonly=True),
        'month':fields.function(_get_month, method=True, type='char', size=10, string = u'月份', store=True, invisible=True),
    }

    _defaults={
        'name': lambda obj, cr, uid, context: '/',
        'date':fields.date.context_today,
        #'employee_id':_employee_get,
        'state':'draft'
    }

    #自动计算到期日期，按开卡日期加 年数*365 天

    def _get_due_date(self, cr, uid, ids, field_name, arg, context=None):
        res = {}
        if context is None:
            context = {}
        DATE_FORMAT = "%Y-%m-%d"
        for rec in self.browse(cr, uid, ids, context=context):
            category = rec.category
            if category:
                remaining_times=category.times_limit
                if rec.active_date:
                    res[rec.id]=(datetime.datetime.strptime(rec.active_date, DATE_FORMAT) +  datetime.timedelta(days=category.age_limit*365)).strftime(DATE_FORMAT)
                else:
                    res[rec.id]=(datetime.date.today()+  datetime.timedelta(days=category.age_limit*365)).strftime(DATE_FORMAT)
        return res
    
    _columns={
        "name":fields.char("卡号",size=64, required=True, readonly=True, states={'0':[('readonly',False)]}),
        "category":fields.many2one("dispatch.service_card_category","服务卡类型", required=True, readonly=True, states={'0':[('readonly',False)]}),
        'age_limit':fields.related('category', 'age_limit', string=u'年限', type='float', readonly=True, store=True),
        "times_limit":fields.integer(u"初始次数", readonly=True),
        "customer":fields.many2one("dispatch.customer","客户",required=True, select=True, readonly=True, states={'0':[('readonly',False)]}),
        "remaining_times":fields.integer("剩余次数",required=True, readonly=True, states={'0':[('readonly',False)]}),
        "active_date":fields.date("开卡日期",required=True, readonly=True, states={'0':[('readonly',False)]}),
        'due_date':fields.function(_get_due_date, method=True, type='date', string = u'到期日期', store=True),
        'state': fields.selection([('0', u'未开卡'),('1', u'已开卡'),('2', u'已用完'),('3', u'已过期'),('4', u'已锁定')], u'状态',required=True, readonly=True),
        'lock_note': fields.char(u'锁定原因', size=200, invisible=False, readonly=True, states={'1':[('readonly',False)], '4':[('readonly',False)]}),
    }
   

    # TODO: can be improved using resource calendar method
    #计算日期间隔对应的天数
    def _get_number_of_days(self, date_from, date_to):
        """Returns a float equals to the timedelta between two dates given as string."""

        DATETIME_FORMAT = "%Y-%m-%d %H:%M:%S"
        from_dt = datetime.datetime.strptime(date_from, DATETIME_FORMAT)
        to_dt = datetime.datetime.strptime(date_to, DATETIME_FORMAT)
        timedelta = to_dt - from_dt
        diff_day = timedelta.days + float(timedelta.seconds) / 86400
        return diff_day
    
    #对象字段
    _columns = {
            'date_from': fields.datetime(u'起始日期',required=True, readonly=True, states={'draft':[('readonly',False)]}, select=True),
            'date_to': fields.datetime(u'结束日期', readonly=True, states={'draft':[('readonly',False)]}),
            'days': fields.float(u'天数', digits=(8, 2), readonly=True, states={'draft':[('readonly',False)]}),
          }
        
    #更改起始日期，自动计算请假天数
    def onchange_date_from(self, cr, uid, ids, date_to, date_from):
        """
        If there are no date set for date_to, automatically set one 8 hours later than
        the date_from.
        Also update the number_of_days.
        """
        # date_to has to be greater than date_from
        if (date_from and date_to) and (date_from > date_to):
            raise osv.except_osv(_(u'警告!'),_(u'开始日期必须小于结束日期.'))

        result = {'value': {}}

        # No date_to set so far: automatically compute one 8 hours later
        if date_from and not date_to:
            date_to_with_delta = datetime.datetime.strptime(date_from, tools.DEFAULT_SERVER_DATETIME_FORMAT) + datetime.timedelta(hours=8)
            result['value']['date_to'] = str(date_to_with_delta)

        # Compute and update the number of days
        if (date_to and date_from) and (date_from <= date_to):
            diff_day = self._get_number_of_days(date_from, date_to)
            result['value']['days'] = round(math.floor(diff_day))+1
        else:
            result['value']['days'] = 0

        return result
    
    #更改结束日期，自动计算请假天数
    def onchange_date_to(self, cr, uid, ids, date_to, date_from):
        """
        Update the number_of_days.
        """
        # date_to has to be greater than date_from
        if (date_from and date_to) and (date_from > date_to):
            raise osv.except_osv(_(u'警告!'),_(u'开始日期必须小于结束日期.'))

        result = {'value': {}}

        # Compute and update the number of days
        if (date_to and date_from) and (date_from <= date_to):
            diff_day = self._get_number_of_days(date_from, date_to)
            result['value']['days'] = round(math.floor(diff_day))+1
        else:
            result['value']['days'] = 0

        return result