django.core.exceptions.ImproperlyConfigured:加载MySQLdb模块时出错：

Question

我正在学习django教程，很多人都问过这个问题，但我认为我的情况有点特殊，因为在安装python-mysql之后，当我尝试做python manage.py同步数据库时，仍然会遇到这个错误。

我在一个虚拟环境中，因为我使用macports来管理我的python安装，所以我创建了我的虚拟环境。

virtualenv code/vdjango --no-site-packages --python=/opt/local/bin/python

在此之前，我使用macports安装了django py27-django，但在创建我的virtualenv之后，我认为最好将django安装到virtualenv上，所以我使用了pip install django==1.5

根据django教程，我编辑了我的settings.py文件，然后执行python manage.py syncdb，最后得到以下错误：

[~/code/vdjango/newsite]$python manage.py syncdb
Traceback (most recent call last):
  File "manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/Users/mac-pro/code/vdjango/lib/python2.7/site-packages/django/core/management/__init__.py", line 453, in execute_from_command_line
    utility.execute()
  File "/Users/mac-pro/code/vdjango/lib/python2.7/site-packages/django/core/management/__init__.py", line 392, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/Users/mac-pro/code/vdjango/lib/python2.7/site-packages/django/core/management/__init__.py", line 272, in fetch_command
    klass = load_command_class(app_name, subcommand)
  File "/Users/mac-pro/code/vdjango/lib/python2.7/site-packages/django/core/management/__init__.py", line 77, in load_command_class
    module = import_module('%s.management.commands.%s' % (app_name, name))
  File "/Users/mac-pro/code/vdjango/lib/python2.7/site-packages/django/utils/importlib.py", line 35, in import_module
    __import__(name)
  File "/Users/mac-pro/code/vdjango/lib/python2.7/site-packages/django/core/management/commands/syncdb.py", line 8, in <module>
    from django.core.management.sql import custom_sql_for_model, emit_post_sync_signal
  File "/Users/mac-pro/code/vdjango/lib/python2.7/site-packages/django/core/management/sql.py", line 9, in <module>
    from django.db import models
  File "/Users/mac-pro/code/vdjango/lib/python2.7/site-packages/django/db/__init__.py", line 40, in <module>
    backend = load_backend(connection.settings_dict['ENGINE'])
  File "/Users/mac-pro/code/vdjango/lib/python2.7/site-packages/django/db/__init__.py", line 34, in __getattr__
    return getattr(connections[DEFAULT_DB_ALIAS], item)
  File "/Users/mac-pro/code/vdjango/lib/python2.7/site-packages/django/db/utils.py", line 93, in __getitem__
    backend = load_backend(db['ENGINE'])
  File "/Users/mac-pro/code/vdjango/lib/python2.7/site-packages/django/db/utils.py", line 27, in load_backend
    return import_module('.base', backend_name)
  File "/Users/mac-pro/code/vdjango/lib/python2.7/site-packages/django/utils/importlib.py", line 35, in import_module
    __import__(name)
  File "/Users/mac-pro/code/vdjango/lib/python2.7/site-packages/django/db/backends/mysql/base.py", line 17, in <module>
    raise ImproperlyConfigured("Error loading MySQLdb module: %s" % e)
django.core.exceptions.ImproperlyConfigured: Error loading MySQLdb module: dlopen(/Users/mac-pro/code/vdjango/lib/python2.7/site-packages/_mysql.so, 2): Library not loaded: libmysqlclient.18.dylib
  Referenced from: /Users/mac-pro/code/vdjango/lib/python2.7/site-packages/_mysql.so
  Reason: image not found

为了确认我已经安装了python-mysql包，我再次运行了pip install，

(vdjango)mac-pro@localhost:[~/code/vdjango/newsite]$pip install python-mysqldb
Downloading/unpacking python-mysqldb
  Could not find any downloads that satisfy the requirement python-mysqldb
No distributions at all found for python-mysqldb
Storing complete log in /Users/mac-pro/.pip/pip.log

那么这里发生了什么呢？看起来我已经有了进一步学习本教程所需的一切，但是python/django正在抱怨没有mysqldb。

Answer 1

我的libmysqlclient.18.dylib位于/usr/local/mysql/lib/，但我的系统在/usr/lib/中查找它。我最终在/usr/lib中创建了libmysqlclient.18.dylib的符号链接，从而修复了这个问题。

1.)确保/usr/local/mysql/lib/中存在libmysqlclient.18.dylib。

打开你的外壳。

sudo -s
ls /usr/local/mysql/lib/ | grep libmysqlclient.18.dylib

您应该会看到该文件：

libmysqlclient.18.dylib

如果没有，请在系统中搜索该文件的位置：

find / -name libmysqlclient.18.dylib

2.)在/usr/lib中创建libmysqlclient.18.dylib的符号链接

在shell中输入以下命令：

ln -s /usr/local/mysql/lib/libmysqlclient.18.dylib /usr/lib/libmysqlclient.18.dylib

如果libmysqlclient.18.dylib文件不在/usr/local/mysql/lib中，请将第一个路径替换为libmysqlclient.18.dylib的正确路径。

希望这能有所帮助。