通过变量计算 DateTimeField()

Question

我是 python 新手，几天来我无法解决我的简单问题。

我有一个 Event 模型，它应该允许用户预订 timeslot、room 和 event type这将显示在时间表中。

class Event(models.Model):
    title = models.CharField(max_length=200)
    description = models.TextField()
    start_time = models.DateTimeField()
    end_time = models.DateTimeField()
    get_date = models.DateTimeField()      # set via form, has year and day
    start_time_choices = [('1', '07:30'), ('2', '07:45'), ('3', '08:00'), ('4', '08:15'), ('5', '08:30')]
    timeslots = models.TimeField(
        choices=start_time_choices,
        "%H:%M",
        default='1',
        null=True)
    room_choices = [('1', 'Room 1'), ('2', 'Room 2'), ('3', 'Room 3'), ('4', 'Room 4'), ('5', 'Room 5')]
    room = models.CharField(
        choices=room_choices,
        max_length=1,
        default='1',
        null=True)
    event_choices = [('1', 'Event A'), ('2', 'Event B')]      # A is 15min long, B is 30min long
    events= models.CharField(
        choices=event_choices,
        max_length=1,
        default='1',
        null=True)

现在我想计算这个事件的 start_time 和 end_time 用于日历视图

• 我将以下计算放在哪里？直接在models.py中？
• 如何处理正确的日期计算？

# this is not a real code

    @property
    def date_calc(self):
        start_date = get_date + timeslots      # Year & Day + Hour & Min

        if events == "Event A":
          end_date = start_date + "00:15"
        else:
          end_date = end_date + "00:30"

        return start_time, end_time

Answer 1

我将以下计算放在哪里？直接在models.py中？

您可以将其添加到您的 models.py，但随着该模块的增长，您可能希望创建一个包含单独模块的 models 文件夹。

如何处理正确的日期计算？

你可以覆盖

def save(self, *args, **kwargs):

然后在那里进行计算。基本上它会在实际保存之前计算 start_time 和 end_time 然后保存它们。

def save(self, *args, **kwargs):
    start_date = get_date + timeslots      # Year & Day + Hour & Min

    if events == "Event A":
      end_date = start_date + "00:15"
    else:
      end_date = end_date + "00:30"

    super(Event, self).save(*args, **kwargs)