遵循Django 2.2官方教程时出现ModuleNotFoundError: No module named 'polls'错误

Hey, let's get that polls app up and running! That error means Django can't locate your polls module, so let's walk through the most common fixes:

1. Double-check your project structure #

First off, make sure your polls app is in the right place and has all the required files. Your project should follow this structure (the key detail is that polls/ sits at the same level as manage.py):

mysite/
    manage.py
    mysite/
        __init__.py
        settings.py
        urls.py
        # other core Django system files
    polls/
        __init__.py  # This empty file is critical—Python needs it to recognize the folder as a module
        admin.py
        apps.py
        migrations/
            __init__.py
        models.py
        views.py
        urls.py  # Your custom URL config here

If you manually created the polls folder, you might have forgotten these __init__.py files—add empty versions of them if they're missing.

2. Confirm your INSTALLED_APPS setup #

You already added 'polls' to INSTALLED_APPS in settings.py, which is correct as long as the folder structure above is right. If polls were nested inside another subfolder, you'd need to use a path like 'mysite.polls', but that's not necessary here.

3. Check where you're running the server command #

You used py mysite\manage.py runserver, which means you're executing the command from the parent folder of mysite/. That works fine, but only if polls/ is inside mysite/ (next to manage.py). If polls lives outside that folder, Django won't be able to find it.

A simpler approach is to move into the mysite/ folder first, then run the server:

cd mysite
py manage.py runserver

This ensures Django looks for apps in the correct directory by default.

4. Recreate the app with Django's startapp command (if needed) #

If you built the polls folder manually, you might be missing some auto-generated files that Django expects. Save your existing views.py and urls.py code, delete the current polls folder, then run this command from the same directory as manage.py:

py manage.py startapp polls

Then paste your saved code back into the new polls folder—this guarantees the structure is 100% Django-friendly.

Quick side note: Fix that HTML typo #

While it's not causing the module error, your views.py has a tiny HTML mistake: <h1><this is a test page</h1> has an extra < before "this". Change it to <h1>This is a test page</h1> so your page renders correctly once the server runs.

内容的提问来源于stack exchange，提问作者BlockeeR