一起运行时，Django StaticLiveServerTestCase测试失败

Question

如果我单独运行一次测试，但是如果我尝试测试整个课程，则第一次测试通过，而第二次测试则通过Server Error ( 500 ) ，有两个测试都对用户进行了相同的记录。 >

所有测试都涉及user登录，我尝试在每个测试中在本地创建用户，但均无济于事，不胜感激。

class SomeTest(StaticLiveServerTestCase):
    def setUp(self):
        self.browser = webdriver.Firefox()
        self.browser.implicitly_wait(10)
        self.user = User.objects.create_user(username="user1",password="somepassword")
        self.user.save()
        qrt, created = Group.objects.get_or_create(name="A Team")
        qrt.user_set.add(self.user)

    def tearDown(self):
        self.browser.quit()

    def test_user_can_login(self):
        self.browser.get(self.live_server_url)
        user = self.browser.find_element_by_id("id_username")
        pa   = self.browser.find_element_by_id("id_password")
        user.send_keys("user1")
        pa.send_keys("somepassword")
        pa.send_keys(Keys.ENTER)
        title = self.browser.find_element_by_id("title").text
        self.assertIn(title, "Welcome")

    def test_user_can_login_again(self):
        self.browser.get(self.live_server_url)
        user = self.browser.find_element_by_id("id_username")
        pa   = self.browser.find_element_by_id("id_password")
        user.send_keys("user1")
        pa.send_keys("somepassword")
        pa.send_keys(Keys.ENTER)
        title = self.browser.find_element_by_id("title").text
        self.assertIn(title, "Welcome")