将项目迁移至django更高的版本, 提示408、409、410中间件错误的解决办法

将项目迁移至django2.X, 中间件提示错误为:

ERRORS:
?: (admin.E408) 'django.contrib.auth.middleware.AuthenticationMiddleware' must be in MIDDLEWARE in order to use the admin application.
?: (admin.E409) 'django.contrib.messages.middleware.MessageMiddleware' must be in MIDDLEWARE in order to use the admin application.
?: (admin.E410) 'django.contrib.sessions.middleware.SessionMiddleware' must be in MIDDLEWARE in order to use the admin application.

解决方法:

修改中间件的书写格式以及变量名即可.

注意：变量名从MIDDLEWARE_CLASSES变成了MIDDLEWARE

在以往django项目中settings的中间件默认书写格式为:

MIDDLEWARE_CLASSES = (
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.auth.middleware.SessionAuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
    'django.middleware.security.SecurityMiddleware',
)

而使用新版Django创建一个新的项目, 中间件书写格式为↓↓↓:

MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
]

可以看到新版django修改了中间件的书写格式: 由元组转变为列表, 并移除了一个中间件, SessionAuthenticationMiddleware.

修改中间件的书写格式以及变量名即可解决此问题.

至于SessionAuthenticationMiddleware中间件,如果曾经有过,注释掉即可

否则报错:

AttributeError: module 'django.contrib.auth.middleware' has no attribute 'SessionAuthenticationMiddleware'

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

...

...

...

django.core.exceptions.ImproperlyConfigured: WSGI application 'yourproject.wsgi.application' could not be loaded; Error importing module.