未定义python '_mysql‘

Question

我用python 3.7.10构建了一个虚拟环境，通过安装mysql和mysqlclient，它是MySQL8.0.28，mysqlClient2.1.0。

运行python manage.py迁移时，其结果如下所示：

(test) ➜  backend git:(main) python manage.py migrate
Traceback (most recent call last):
  File "/usr/local/Caskroom/miniforge/base/envs/test/lib/python3.7/site-packages/MySQLdb/__init__.py", line 18, in <module>
    from . import _mysql
ImportError: dlopen(/usr/local/Caskroom/miniforge/base/envs/test/lib/python3.7/site-packages/MySQLdb/_mysql.cpython-37m-darwin.so, 0x0002): symbol not found in flat namespace '_mysql_affected_rows'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "manage.py", line 22, in <module>
    main()
  File "manage.py", line 18, in main
    execute_from_command_line(sys.argv)
  File "/usr/local/Caskroom/miniforge/base/envs/test/lib/python3.7/site-packages/django/core/management/__init__.py", line 419, in execute_from_command_line
    utility.execute()
  File "/usr/local/Caskroom/miniforge/base/envs/test/lib/python3.7/site-packages/django/core/management/__init__.py", line 395, in execute
    django.setup()
  File "/usr/local/Caskroom/miniforge/base/envs/test/lib/python3.7/site-packages/django/__init__.py", line 24, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "/usr/local/Caskroom/miniforge/base/envs/test/lib/python3.7/site-packages/django/apps/registry.py", line 114, in populate
    app_config.import_models()
  File "/usr/local/Caskroom/miniforge/base/envs/test/lib/python3.7/site-packages/django/apps/config.py", line 301, in import_models
    self.models_module = import_module(models_module_name)
  File "/usr/local/Caskroom/miniforge/base/envs/test/lib/python3.7/importlib/__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
  File "<frozen importlib._bootstrap>", line 983, in _find_and_load
  File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 677, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 728, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "/usr/local/Caskroom/miniforge/base/envs/test/lib/python3.7/site-packages/django/contrib/auth/models.py", line 3, in <module>
    from django.contrib.auth.base_user import AbstractBaseUser, BaseUserManager
  File "/usr/local/Caskroom/miniforge/base/envs/test/lib/python3.7/site-packages/django/contrib/auth/base_user.py", line 48, in <module>
    class AbstractBaseUser(models.Model):
  File "/usr/local/Caskroom/miniforge/base/envs/test/lib/python3.7/site-packages/django/db/models/base.py", line 122, in __new__
    new_class.add_to_class('_meta', Options(meta, app_label))
  File "/usr/local/Caskroom/miniforge/base/envs/test/lib/python3.7/site-packages/django/db/models/base.py", line 326, in add_to_class
    value.contribute_to_class(cls, name)
  File "/usr/local/Caskroom/miniforge/base/envs/test/lib/python3.7/site-packages/django/db/models/options.py", line 207, in contribute_to_class
    self.db_table = truncate_name(self.db_table, connection.ops.max_name_length())
  File "/usr/local/Caskroom/miniforge/base/envs/test/lib/python3.7/site-packages/django/utils/connection.py", line 15, in __getattr__
    return getattr(self._connections[self._alias], item)
  File "/usr/local/Caskroom/miniforge/base/envs/test/lib/python3.7/site-packages/django/utils/connection.py", line 62, in __getitem__
    conn = self.create_connection(alias)
  File "/usr/local/Caskroom/miniforge/base/envs/test/lib/python3.7/site-packages/django/db/utils.py", line 204, in create_connection
    backend = load_backend(db['ENGINE'])
  File "/usr/local/Caskroom/miniforge/base/envs/test/lib/python3.7/site-packages/django/db/utils.py", line 111, in load_backend
    return import_module('%s.base' % backend_name)
  File "/usr/local/Caskroom/miniforge/base/envs/test/lib/python3.7/importlib/__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "/usr/local/Caskroom/miniforge/base/envs/test/lib/python3.7/site-packages/django/db/backends/mysql/base.py", line 15, in <module>
    import MySQLdb as Database
  File "/usr/local/Caskroom/miniforge/base/envs/test/lib/python3.7/site-packages/MySQLdb/__init__.py", line 24, in <module>
    version_info, _mysql.version_info, _mysql.__file__
NameError: name '_mysql' is not defined

当我试图重新安装它时，它说它已经安装了。我认为python找不到mysql路径。我看了很多问题，但解决不了我的问题。自从我第一次开始巨蟒，我找不到原因。

提前谢谢你的帮助。

我从哪里开始发现这个问题？

Answer 1

几天前我也有同样的问题。确保安装了mysqlclient，然后安装pip install PyMySQL，现在在settings.py中使用以下代码行：

#in settings.py

import pymysql  
pymysql.install_as_MySQLdb()

这对我有用。

Answer 2

这是因为mysql库(_mysql*.so)的MySQLdb版本与MySQLdb版本不兼容。激活虚拟环境并尝试如下：

 pip uninstall mysqlclient
 pip install mysqlclient --no-cache-dir