无法正确检查实例的模型类型

Question

无法弄清楚，为什么“if statement”会返回不正确的值

    next_step_type = type(next_step)()  # this returns 'Quiz' which is correct

    # if statement returns step_type_letter = 't' which is not correct
    if next_step_type is "Quiz":
        step_type_letter = 'q'
    else:
        step_type_letter = 't'

Answer 1

也许尝试这样：

next_step_type = type(next_step)
if next_step_type is Quiz:
    step_type_letter = 'q'
else:
    step_type_letter = 't' 

编辑： 或者如果你使用isinstance（）：

if isinstance(next_step_type(), Quiz):
    step_type_letter = 'q'
else:
    step_type_letter = 't'

Answer 2

这也应该有用，可能更容易阅读？

from .models import Quiz

# next_step is a model object, e.g. next_step = Quiz.objects.create(...)
if isinstance(next_step, Quiz):
    ...
else:
    ...