django 减去日期时间字段

Question

我使用的模型具有名为 start_time 和 finish_time 的字段，两者都是 DateTimeField，我试图通过 start_time 减去 finish_time 来计算响应时间。

在外壳中：

>>> obj = Quizgame.objects.get(user=harry)
>>> start = obj.start_time
>>> end = obj.finish_time
>>> result = end - start
>>> result
datetime.timedelta(seconds=31, microseconds=912224)

但在 django 视图中，当我执行此操作时，我会收到 unsupported operand type(s) for -: 'method' and 'datetime.datetime'

的错误

views.py

def final_part(request):
    obj = Quizgame.objects.get(user=request.user)
    start = obj.start_time
    end = obj.end_time
    result = end - start
    return HttpResponse(result)

models.py
class Quizgame(models.Model):
    user = models.OneToOneField(User, on_delete=models.CASCADE)
    total_score = models.DecimalField("Total score", default=0, decimal_places=2, max_digits=6)
    start_time = models.DateTimeField(auto_now_add=True)
    finish_time = models.DateTimeField(null=True)

我稍后使用 datetime.datetime.now() 设置完成时间

Answer 1

你使用了 obj.end_time 而不是 obj.finish_time

def final_part(request):
    obj = Quizgame.objects.get(user=request.user)
    start = obj.start_time
    end = obj.finish_time
    result = end - start
    return HttpResponse(result)