Question

我正试图在Djago中获得两个Datetiemfield的区别。我尝试覆盖默认的save（），但仍然出现错误。

models.py

class Sample(models.Model):
    ad_start = models.DateTimeField() 
    ad_end = models.DateTimeField()
    ad_duration = models.IntegerField()

@property
def get_time_diff(self):
    timediff = self.ad_end - self.ad_start
    return timediff
    #return relativedelta(self.ad_end, self.ad_start)

def save(self, *args, **kwargs):
    self.ad_duration = self.get_time_diff()
    super(Sample, self).save(*args, **kwargs)

forms.py

class SampleForm(forms.ModelForm):
class Meta:
    model = Sample
    exclude = ("submitted", 'ad_duration', "list_date" )
    widgets = {
        'ad_start': DatePickerInput(), 
        'ad_end': DatePickerInput(),
    }

错误

Django Version: 2.1.7
Exception Type: TypeError
Exception Value:'datetime.timedelta' object is not callable

Answer 1

您的代码需要进行两项更改。

首先，您需要从方法@property中删除get_time_diff。因为您无法通过()调用属性方法。或者，您仍然可以保留property方法，但不要在save函数中调用它，例如：self.ad_duration = self.get_time_diff

第二，您需要将模型字段更新为DurationField，以存储在get_time_diff中创建的时间增量对象。像这样：

class Sample(models.Model):
        ad_start = models.DateTimeField() 
        ad_end = models.DateTimeField()
        ad_duration = models.DurationField()


    def get_time_diff(self):
        timediff = self.ad_end - self.ad_start
        return timediff


    def save(self, *args, **kwargs):
        self.ad_duration = self.get_time_diff()
        super(Sample, self).save(*args, **kwargs)

或者您可以从get_time_diff获取总秒数并将其存储在ad_duration字段（将是浮点字段）中。

class Sample(models.Model):
    ad_start = models.DateTimeField() 
    ad_end = models.DateTimeField()
    ad_duration = models.FloatField()

    def get_time_diff(self):
        timediff = self.ad_end - self.ad_start
        return timediff.total_seconds()  # returns value in seconds

导致DateError的Django DateTimeField（）（'datetime.timedelta'对象不可调用）

1 个答案: