运行测试时，“TypeError：'module'对象不可调用”

Question

我正在从控制台运行以下命令

$ py.test -m selenium

但后来我不断收到这个错误：

___________________________________________________ ERROR collecting setup_distribution/verify_distribution_list.py ____________________________________________________
setup_distribution/verify_distribution_list.py:1: in <module>
>   from foodnet.tests.selenium.base import SeleniumFoodnetTestCase
/home/frank/.virtualenvs/foodnet27/local/lib/python2.7/site-packages/_pytest/assertion/rewrite.py:159: in load_module
>           py.builtin.exec_(co, mod.__dict__)
base.py:8: in <module>
>   class SeleniumFoodnetTestCase(TestCase):
E       TypeError: 'module' object is not callable

以下是我正在使用的代码：

base.py

from unittest import TestCase
from foodnet.tests import selenium
from selenium import webdriver
from selenium.common.exceptions import NoSuchElementException, NoAlertPresentException


@selenium
class SeleniumFoodnetTestCase(TestCase):

    superuser_username = 'admin'
    superuser_password = 'some_pwd'
    server_base_url = "http://localhost:8000"

    def setUp(self): # The rest of the code hidden

verify_distribution_list.py

from foodnet.tests.selenium.base import SeleniumFoodnetTestCase


class CreateDistributionList(SeleniumFoodnetTestCase):

    def test_create_distribution_list(self):
        driver = self.driver
        # The rest of the code hidden for brevity

为什么我收到上述错误的任何想法？

更新：以下是我的目录结构

foodnet
|
|- tests
      |
      |- selenium
            |
            |- base.py
            |
            |- setup_distribution
                    |
                    |- verify_distribution_list.py