问题描述：
在使用django中间件拦截请求做处理的时候，自定义并配置好settings.py时候，报错了。
如下
ModuleNotFoundError: No module named 'middleware'
System check identified no issues (0 silenced).
January 01, 2020 - 17:55:46
Django version 2.2.6, using settings 'project3.settings'
Starting development server at http://127.0.0.1:8000/
Quit the server with CTRL-BREAK.
Exception in thread django-main-thread:
Traceback (most recent call last):
File "G:\anaconda\lib\site-packages\django\core\servers\basehttp.py", line 45, in get_internal_wsgi_application
return import_string(app_path)
File "G:\anaconda\lib\site-packages\django\utils\module_loading.py", line 17, in import_string
module = import_module(module_path)
File "G:\anaconda\lib\importlib\__init__.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 994, in _gcd_import
File "<frozen importlib._bootstrap>", line 971, in _find_and_load
File "<frozen importlib._bootstrap>", line 955, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 665, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 678, in exec_module
File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
File "F:\django_lear\project3\project3\wsgi.py", line 16, in <module>
application = get_wsgi_application()
File "G:\anaconda\lib\site-packages\django\core\wsgi.py", line 13, in get_wsgi_application
return WSGIHandler()
File "G:\anaconda\lib\site-packages\django\core\handlers\wsgi.py", line 135, in __init__
self.load_middleware()
File "G:\anaconda\lib\site-packages\django\core\handlers\base.py", line 35, in load_middleware
middleware = import_string(middleware_path)
File "G:\anaconda\lib\site-packages\django\utils\module_loading.py", line 17, in import_string
module = import_module(module_path)
File "G:\anaconda\lib\importlib\__init__.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 994, in _gcd_import
File "<frozen importlib._bootstrap>", line 971, in _find_and_load
File "<frozen importlib._bootstrap>", line 941, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
File "<frozen importlib._bootstrap>", line 994, in _gcd_import
File "<frozen importlib._bootstrap>", line 971, in _find_and_load
File "<frozen importlib._bootstrap>", line 941, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
File "<frozen importlib._bootstrap>", line 994, in _gcd_import
File "<frozen importlib._bootstrap>", line 971, in _find_and_load
File "<frozen importlib._bootstrap>", line 953, in _find_and_load_unlocked
ModuleNotFoundError: No module named 'middleware'
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "G:\anaconda\lib\threading.py", line 916, in _bootstrap_inner
self.run()
File "G:\anaconda\lib\threading.py", line 864, in run
self._target(*self._args, **self._kwargs)
File "G:\anaconda\lib\site-packages\django\utils\autoreload.py", line 54, in wrapper
fn(*args, **kwargs)
File "G:\anaconda\lib\site-packages\django\core\management\commands\runserver.py", line 137, in inner_run
handler = self.get_handler(*args, **options)
File "G:\anaconda\lib\site-packages\django\contrib\staticfiles\management\commands\runserver.py", line 27, in get_handler
handler = super().get_handler(*args, **options)
File "G:\anaconda\lib\site-packages\django\core\management\commands\runserver.py", line 64, in get_handler
return get_internal_wsgi_application()
File "G:\anaconda\lib\site-packages\django\core\servers\basehttp.py", line 50, in get_internal_wsgi_application
) from err
django.core.exceptions.ImproperlyConfigured: WSGI application 'project3.wsgi.application' could not be loaded; Error importing module.
自定义中间件代码如下：
from django.utils.deprecation import MiddlewareMixin
class MyMiddleware(MiddlewareMixin):
def process_request(self,request):
print("get 参数为：",request.GET.get("a") )
settings.py中MIDDLEWAE代码如下：
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',
'middleware.myApp.myMiddleware.MyMiddleware',
]
原因分析：
没有找到'middleware'模块。自定义的中间件没有找到，疑惑
解决方案：
settings.py中配置自定义中间件时写上完整路径，从appname开始写
项目名.app名.模块名.中间件类名
修改后代码如下：
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',
'myApp.middleware.myApp.myMiddleware.MyMiddleware',
]
重启服务器，执行。没问题了。
感谢参考：
https://blog.csdn.net/weixin_42290927/article/details/82663299
