使用 PyCharm 时出现 Django 错误：“'function' 对象没有属性 'using'”

Question

在使用 Django 和 Django REST Framework 编写 REST API 时，我突然收到以下错误：

Unhandled exception in thread started by <function check_errors.<locals>.wrapper at 0x1032bc1e0>
Traceback (most recent call last):
  File "/Users/alexarias/PycharmProjects/ContratRestAPI/venv/lib/python3.6/site-packages/django/utils/autoreload.py", line 226, in wrapper
    fn(*args, **kwargs)
  File "/Users/alexarias/PycharmProjects/ContratRestAPI/venv/lib/python3.6/site-packages/django/core/management/commands/runserver.py", line 113, in inner_run
    autoreload.raise_last_exception()
  File "/Users/alexarias/PycharmProjects/ContratRestAPI/venv/lib/python3.6/site-packages/django/utils/autoreload.py", line 249, in raise_last_exception
    six.reraise(*_exception)
  File "/Users/alexarias/PycharmProjects/ContratRestAPI/venv/lib/python3.6/site-packages/django/utils/six.py", line 685, in reraise
    raise value.with_traceback(tb)
  File "/Users/alexarias/PycharmProjects/ContratRestAPI/venv/lib/python3.6/site-packages/django/utils/autoreload.py", line 226, in wrapper
    fn(*args, **kwargs)
  File "/Users/alexarias/PycharmProjects/ContratRestAPI/venv/lib/python3.6/site-packages/django/__init__.py", line 27, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "/Users/alexarias/PycharmProjects/ContratRestAPI/venv/lib/python3.6/site-packages/django/apps/registry.py", line 108, in populate
    app_config.import_models(all_models)
  File "/Users/alexarias/PycharmProjects/ContratRestAPI/venv/lib/python3.6/site-packages/django/apps/config.py", line 199, in import_models
    self.models_module = import_module(models_module_name)
  File "/usr/local/Cellar/python3/3.6.0/Frameworks/Python.framework/Versions/3.6/lib/python3.6/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 978, in _gcd_import
  File "<frozen importlib._bootstrap>", line 961, in _find_and_load
  File "<frozen importlib._bootstrap>", line 950, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 655, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 678, in exec_module
  File "<frozen importlib._bootstrap>", line 205, in _call_with_frames_removed
  File "/Users/alexarias/PycharmProjects/ContratRestAPI/employees/models.py", line 1, in <module>
    from django.contrib.auth.admin import User
  File "/Users/alexarias/PycharmProjects/ContratRestAPI/venv/lib/python3.6/site-packages/django/contrib/auth/admin.py", line 7, in <module>
    from django.contrib.auth.forms import (
  File "/Users/alexarias/PycharmProjects/ContratRestAPI/venv/lib/python3.6/site-packages/django/contrib/auth/forms.py", line 120, in <module>
    class UserChangeForm(forms.ModelForm):
  File "/Users/alexarias/PycharmProjects/ContratRestAPI/venv/lib/python3.6/site-packages/django/forms/models.py", line 247, in __new__
    opts.field_classes)
  File "/Users/alexarias/PycharmProjects/ContratRestAPI/venv/lib/python3.6/site-packages/django/forms/models.py", line 166, in fields_for_model
    formfield = f.formfield(**kwargs)
  File "/Users/alexarias/PycharmProjects/ContratRestAPI/venv/lib/python3.6/site-packages/django/db/models/fields/related.py", line 1579, in formfield
    'queryset': self.remote_field.model._default_manager.using(db),
  File "/Users/alexarias/PycharmProjects/ContratRestAPI/venv/lib/python3.6/site-packages/django/db/models/manager.py", line 85, in manager_method
    return getattr(self.get_queryset, name)(*args, **kwargs)
AttributeError: 'function' object has no attribute 'using'

我尝试取消注释我刚刚完成但未解决的所有代码。检查了奇怪的格式字符，但没有...错误几乎是自发出现的。以前运行的代码现在没有了。

Answer 1

这发生在：

1. 您为 GenericAPIView 类定义了错误的方法覆盖
2. PyCharm 然后建议将方法转换为属性
3. 您批准，PyCharm 将方法转换为属性

不完全确定会发生什么，但 PyCharm 修改了 Django 包文件。即使您删除 @property 装饰器，问题仍然存在。 如果您立即发现此问题（在关闭 IDE 之前），那么您可以 ctrl+z 撤消更改，这将解决问题。

如果您已经关闭了 IDE 或者您无法 ctrl+z 撤消更改，那么解决方案是卸载并重新安装 Django。

希望这会有所帮助！包装器问题有时很难调试！