Django调用同应用其他文件夹函数时出现ModuleNotFoundError求助

问题场景 #

Django应用目录结构：

.administration
├── background_tasks
│   ├── magic_update_set.py
├── migrations
│   ├── __init__.py
├── __init__.py
├── admin.py
├── config.py
├── models.py
├── tests.py
├── urls.py
└── views.py

magic_update_set.py中的函数：

def magic_set_update_bg_task(options):
    ...

views.py中的导入代码：

from background_tasks.magic_update_set import magic_set_update_bg_task

...

def update_magic_set_function_queue(request):
    options = {
        'code': request.POST['code'],
    }
    magic_set_update_bg_task(options, verbose_name='Set Update')
    return HttpResponse(status=200)

运行时错误：

ModuleNotFoundError: No module named 'background_tasks'

完整报错栈：

Traceback (most recent call last):
  File "C:\Users\rossw\Documents\Projects\card_companion\manage.py", line 22, in <module>
    main()                                                                               
  File "C:\Users\rossw\Documents\Projects\card_companion\manage.py", line 19, in main    
    execute_from_command_line(sys.argv)                                                   
  File "C:\Users\rossw\Documents\Projects\card_companion\card_companion_venv\lib\site-packages\django\core\management\__init__.py", line 419, in execute_from_command_line
    utility.execute()
  File "C:\Users\rossw\Documents\Projects\card_companion\card_companion_venv\lib\site-packages\django\core\management\__init__.py", line 413, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "C:\Users\rossw\Documents\Projects\card_companion\card_companion_venv\lib\site-packages\django\core\management\base.py", line 354, in run_from_argv
    self.execute(*args, **cmd_options)
  File "C:\Users\rossw\Documents\Projects\card_companion\card_companion_venv\lib\site-packages\django\core\management\base.py", line 393, in execute
    self.check()
  File "C:\Users\rossw\Documents\Projects\card_companion\card_companion_venv\lib\site-packages\django\core\management\base.py", line 419, in check
    all_issues = checks.run_checks(
  File "C:\Users\rossw\Documents\Projects\card_companion\card_companion_venv\lib\site-packages\django\core\checks\registry.py", line 76, in run_checks
    new_errors = check(app_configs=app_configs, databases=databases)
  File "C:\Users\rossw\Documents\Projects\card_companion\card_companion_venv\lib\site-packages\django\core\checks\urls.py", line 13, in check_url_config
    return check_resolver(resolver)
  File "C:\Users\rossw\Documents\Projects\card_companion\card_companion_venv\lib\site-packages\django\core\checks\urls.py", line 23, in check_resolver
    return check_method()
  File "C:\Users\rossw\Documents\Projects\card_companion\card_companion_venv\lib\site-packages\django\urls\resolvers.py", line 416, in check
    for pattern in self.url_patterns:
  File "C:\Users\rossw\Documents\Projects\card_companion\card_companion_venv\lib\site-packages\django\utils\functional.py", line 48, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "C:\Users\rossw\Documents\Projects\card_companion\card_companion_venv\lib\site-packages\django\urls\resolvers.py", line 602, in url_patterns
    patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
  File "C:\Users\rossw\Documents\Projects\card_companion\card_companion_venv\lib\site-packages\django\utils\functional.py", line 48, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "C:\Users\rossw\Documents\Projects\card_companion\card_companion_venv\lib\site-packages\django\urls\resolvers.py", line 595, in urlconf_module
    return import_module(self.urlconf_name)
  File "C:\Python310\lib\importlib\__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1050, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1027, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1006, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 688, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 883, in exec_module
  File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
  File "C:\Users\rossw\Documents\Projects\card_companion\core\urls.py", line 12, in <module>
    path('administration/',    include('apps.administration.urls')),
  File "C:\Users\rossw\Documents\Projects\card_companion\card_companion_venv\lib\site-packages\django\urls\conf.py", line 34, in include
    urlconf_module = import_module(urlconf_module)
  File "C:\Python310\lib\importlib\__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1050, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1027, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1006, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 688, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 883, in exec_module
  File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
  File "C:\Users\rossw\Documents\Projects\card_companion\apps\administration\urls.py", line 3, in <module>
    from apps.administration.views import administration_tasks, update_magic_set_function_queue
  File "C:\Users\rossw\Documents\Projects\card_companion\apps\administration\views.py", line 6, in <module>
    from background_tasks.magic_update_set import magic_set_update_bg_task
ModuleNotFoundError: No module named 'background_tasks'

解决步骤 #

1. 修正导入路径 #

当前导入用了绝对路径写法，但background_tasks是administration应用下的子目录，有两种修正方式：

• 相对导入：在views.py中修改导入语句，开头的.代表当前目录：

  from .background_tasks.magic_update_set import magic_set_update_bg_task
  

• 完整应用路径导入：根据报错栈里的应用路径，用完整包路径导入：

  from apps.administration.background_tasks.magic_update_set import magic_set_update_bg_task
  

2. 确保目录为Python包 #

检查background_tasks文件夹下是否存在__init__.py文件，没有的话新建一个空文件，Python会将包含该文件的目录识别为可导入的包。

3. 修复函数调用参数不匹配问题 #

注意到magic_set_update_bg_task定义时仅接收options一个参数，但调用时传了options和verbose_name='Set Update'两个参数，后续会触发TypeError，需要二选一修改：

• 修改函数定义，新增参数：

  def magic_set_update_bg_task(options, verbose_name=None):
      ...
  

• 或者调用时只传options参数：

  magic_set_update_bg_task(options)
  

内容的提问来源于stack exchange，提问作者Ross