[Python知识库]django启动报错：Error loading MySQLdb module

1. 新建一个django项目，数据库想使用mysql，就改了下settings.py中DATABASES这个配置项，然后python manage.py runserver启动时报错了：

Traceback (most recent call last):
  File "path\Programs\Python\Python36\lib\site-packages\django\utils\autoreload.py", line 225, in wrapper
    fn(*args, **kwargs)
  File "path\Programs\Python\Python36\lib\site-packages\django\core\management\commands\runserver.py", line 109, in inner_run
    autoreload.raise_last_exception()
  File "path\Programs\Python\Python36\lib\site-packages\django\utils\autoreload.py", line 248, in raise_last_exception
    raise _exception[1]
  File "path\Programs\Python\Python36\lib\site-packages\django\core\management\__init__.py", line 337, in execute
    autoreload.check_errors(django.setup)()
  File "path\Programs\Python\Python36\lib\site-packages\django\utils\autoreload.py", line 225, in wrapper
    fn(*args, **kwargs)
  File "path\Programs\Python\Python36\lib\site-packages\django\__init__.py", line 24, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "path\Programs\Python\Python36\lib\site-packages\django\apps\registry.py", line 112, in populate
    app_config.import_models()
  File "path\Programs\Python\Python36\lib\site-packages\django\apps\config.py", line 198, in import_models
    self.models_module = import_module(models_module_name)
  File "path\Programs\Python\Python36\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 "path\Programs\Python\Python36\lib\site-packages\django\contrib\auth\models.py", line 2, in <module>
    from django.contrib.auth.base_user import AbstractBaseUser, BaseUserManager
  File "path\Programs\Python\Python36\lib\site-packages\django\contrib\auth\base_user.py", line 47, in <module>
    class AbstractBaseUser(models.Model):
  File "path\Programs\Python\Python36\lib\site-packages\django\db\models\base.py", line 101, in __new__
    new_class.add_to_class('_meta', Options(meta, app_label))
  File "path\Programs\Python\Python36\lib\site-packages\django\db\models\base.py", line 305, in add_to_class
    value.contribute_to_class(cls, name)
  File "path\Programs\Python\Python36\lib\site-packages\django\db\models\options.py", line 203, in contribute_to_class
    self.db_table = truncate_name(self.db_table, connection.ops.max_name_length())
  File "path\Programs\Python\Python36\lib\site-packages\django\db\__init__.py", line 33, in __getattr__
    return getattr(connections[DEFAULT_DB_ALIAS], item)
  File "path\Programs\Python\Python36\lib\site-packages\django\db\utils.py", line 202, in __getitem__
    backend = load_backend(db['ENGINE'])
  File "path\Programs\Python\Python36\lib\site-packages\django\db\utils.py", line 110, in load_backend
    return import_module('%s.base' % backend_name)
  File "path\Programs\Python\Python36\lib\importlib\__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "path\Programs\Python\Python36\lib\site-packages\django\db\backends\mysql\base.py", line 20, in <module>
    ) from err
django.core.exceptions.ImproperlyConfigured: Error loading MySQLdb module.
Did you install mysqlclient?

查了下是因为python3中已经不支持mysqldb，取而代之的是pymysql。但是django中的数据库引擎默认还是mysqldb，所以会出现这个错误。
2. 解决
可以在django项目应用的根目录的__init__.py文件中添加如下：

import pymysql
pymysql.install_as_MySQLdb()