Django测试报错TypeError: Field 'id'期望数字却得到()求解决

我在代码中三次遇到该错误，已查阅相关问题但未找到可行解决方案，恳请各位提供解决思路。

相关代码 #

models.py

class Exam(models.Model):
    code = models.CharField(max_length=50)
    name = models.CharField(max_length=100)
    semester = models.IntegerField(default=1)
    year = models.CharField(max_length=9)
    users = models.ManyToManyField(User, blank=True)

    def __init__(self, *args, **kwargs):
        super().__init__(args, kwargs)
        self.questions = None

test_models.py

class ExamModelTestCase(TestCase):
    def setUp(self):
        self.user = User.objects.create(username='test_user', first_name='Test', last_name='User')
        self.exam = Exam.objects.create(code="EXAM1", name="Exam 1", semester=1, year="2024")

    def test_exam_str_method(self):
        self.assertEqual(str(self.exam), "EXAM1-Exam 1 2024 1")

错误信息 #

Found 12 test(s).
Creating test database for alias 'default'...
System check identified no issues (0 silenced).
.....EEEEEE.
======================================================================
ERROR: test_exam_str_method (examc_app.tests.test_models.ExamModelTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/lucile/examreview/venv/lib/python3.10/site-packages/django/db/models/fields/__init__.py", line 2053, in get_prep_value
    return int(value)
TypeError: int() argument must be a string, a bytes-like object or a real number, not 'tuple'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/home/lucile/examreview/examc_app/tests/test_models.py", line 9, in setUp
    self.exam = Exam.objects.create(code="EXAM1", name="Exam 1", semester=1, year="2024")
  
TypeError: Field 'id' expected a number but got ().

解决思路 #

问题出在Exam类的__init__方法里：调用父类构造函数时，你直接传递了args和kwargs，没有对它们进行解包。Django的Model构造函数需要接收展开后的位置参数和关键字参数，直接传元组和字典会导致参数格式错误，进而让id字段无法正确初始化，出现空元组的错误。

修改models.py中的__init__方法，给args和kwargs加上解包运算符：

def __init__(self, *args, **kwargs):
    super().__init__(*args, **kwargs)  # 添加*和**解包参数
    self.questions = None

这样修改后，Django就能正确处理初始化参数，正常创建Exam实例，测试也能顺利运行了。

内容的提问来源于stack exchange，提问作者TheGoldenKiwi2