Django没有名为'django.db.migrations.migration'的模块

Question

我的项目中有一个自定义用户模型。我想通过删除数据库中的所有表并删除迁移来删除它并返回默认用户模型。在此之后，我尝试运行python manage.py makemigrations命令，但它写道：

Traceback (most recent call last):
  File "manage.py", line 15, in <module>
    execute_from_command_line(sys.argv)
  File "/home/irakliy01/Projects/Project/PythonVEnv/lib/python3.6/site-packages/django/core/management/__init__.py", line 371, in execute_from_command_line
    utility.execute()
  File "/home/irakliy01/Projects/Project/PythonVEnv/lib/python3.6/site-packages/django/core/management/__init__.py", line 347, in execute
    django.setup()
  File "/home/irakliy01/Projects/Project/PythonVEnv/lib/python3.6/site-packages/django/__init__.py", line 24, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "/home/irakliy01/Projects/Project/PythonVEnv/lib/python3.6/site-packages/django/apps/registry.py", line 89, in populate
    app_config = AppConfig.create(entry)
  File "/home/irakliy01/Projects/Project/PythonVEnv/lib/python3.6/site-packages/django/apps/config.py", line 116, in create
    mod = import_module(mod_path)
  File "/usr/lib/python3.6/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 "/home/irakliy01/Projects/Project/PythonVEnv/lib/python3.6/site-packages/django/contrib/contenttypes/apps.py", line 9, in <module>
    from .management import (
  File "/home/irakliy01/Projects/Project/PythonVEnv/lib/python3.6/site-packages/django/contrib/contenttypes/management/__init__.py", line 2, in <module>
    from django.db import DEFAULT_DB_ALIAS, migrations, router, transaction
  File "/home/irakliy01/Projects/Project/PythonVEnv/lib/python3.6/site-packages/django/db/migrations/__init__.py", line 1, in <module>
    from .migration import Migration, swappable_dependency  # NOQA
ModuleNotFoundError: No module named 'django.db.migrations.migration'

我不知道我做错了什么。

Answer 1

您的 Django 安装似乎已损坏。您可以重新安装：

pip3 uninstall Django
pip3 install Django

通常，如果您在常规操作系统的 python 安装中安装了 Django，然后安装了 virtualenv 副本并尝试运行 django 服务器，则会发生这种情况。您需要在您的 virtualenv 中重新安装 Django，如果它已经存在，请先将其删除。

Answer 2

假设您在虚拟环境中运行，您可能实际上也删除了 /django/db/migrations/ 下的文件。所以这里的错误就很明显了。您需要重新安装 django 才能恢复文件以成功迁移。

为此，请检查 django 版本

python -m django --version

然后使用以下命令安装相同版本

pip install --upgrade --force-reinstall  Django==3.2.2

Answer 3

我不假思索地复制粘贴并在根目录中运行这个 oneliner。

find . -path "*/migrations/*.py" -not -name "__init__.py" -delete

嗯，我在 venv 中安装了 Django，并且令人惊讶的是migrationsDjango 源代码中有一个包。重新安装后一切正常。