我正在Amazon EC2服务器上安装python 3.5，django 1.10和psycopg2 2.7.1，以便使用Postgresql数据库。我在虚拟环境中使用 python 3，并遵循经典的安装步骤：
cd /home/mycode
virtualenv-3.5 p3env
source p3env/bin/activate
pip install django
cd kenbot
django-admin startproject kenbot
pip install psycopg2
然后，我编辑了项目中的 settings.py 文件以定义数据库设置：
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.postgresql_psycopg2',
'NAME': 'deleted',
'USER': 'deleted',
'PASSWORD': 'deleted',
'HOST': 'deleted',
'PORT': '5432',
}
最后我输入(仍然在虚拟环境中(：
python manage.py makemigrations
并得到以下错误：
Traceback (most recent call last):
File "/home/mycode/p3env/local/lib/python3.5/dist-packages/django/db/backends/postgresql/base.py", line 20, in <module>
import psycopg2 as Database
ImportError: No module named 'psycopg2'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "manage.py", line 22, in <module>
execute_from_command_line(sys.argv)
File "/home/mycode/p3env/local/lib/python3.5/dist-packages/django/core/management/__init__.py", line 367, in execute_from_command_line
utility.execute()
File "/home/mycode/p3env/local/lib/python3.5/dist-packages/django/core/management/__init__.py", line 341, in execute
django.setup()
File "/home/mycode/p3env/local/lib/python3.5/dist-packages/django/__init__.py", line 27, in setup
apps.populate(settings.INSTALLED_APPS)
File "/home/mycode/p3env/local/lib/python3.5/dist-packages/django/apps/registry.py", line 108, in populate
app_config.import_models(all_models)
File "/home/mycode/p3env/local/lib/python3.5/dist-packages/django/apps/config.py", line 199, in import_models
self.models_module = import_module(models_module_name)
File "/home/mycode/p3env/lib64/python3.5/importlib/__init__.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 986, in _gcd_import
File "<frozen importlib._bootstrap>", line 969, in _find_and_load
File "<frozen importlib._bootstrap>", line 958, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 673, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 662, in exec_module
File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed
File "/home/mycode/p3env/local/lib/python3.5/dist-packages/django/contrib/auth/models.py", line 4, in <module>
from django.contrib.auth.base_user import AbstractBaseUser, BaseUserManager
File "/home/mycode/p3env/local/lib/python3.5/dist-packages/django/contrib/auth/base_user.py", line 52, in <module>
class AbstractBaseUser(models.Model):
File "/home/mycode/p3env/local/lib/python3.5/dist-packages/django/db/models/base.py", line 119, in __new__
new_class.add_to_class('_meta', Options(meta, app_label))
File "/home/mycode/p3env/local/lib/python3.5/dist-packages/django/db/models/base.py", line 316, in add_to_class
value.contribute_to_class(cls, name)
File "/home/mycode/p3env/local/lib/python3.5/dist-packages/django/db/models/options.py", line 214, in contribute_to_class
self.db_table = truncate_name(self.db_table, connection.ops.max_name_length())
File "/home/mycode/p3env/local/lib/python3.5/dist-packages/django/db/__init__.py", line 33, in __getattr__
return getattr(connections[DEFAULT_DB_ALIAS], item)
File "/home/mycode/p3env/local/lib/python3.5/dist-packages/django/db/utils.py", line 211, in __getitem__
backend = load_backend(db['ENGINE'])
File "/home/mycode/p3env/local/lib/python3.5/dist-packages/django/db/utils.py", line 115, in load_backend
return import_module('%s.base' % backend_name)
File "/home/mycode/p3env/lib64/python3.5/importlib/__init__.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "/home/mycode/p3env/local/lib/python3.5/dist-packages/django/db/backends/postgresql/base.py", line 24, in <module>
raise ImproperlyConfigured("Error loading psycopg2 module: %s" % e)
django.core.exceptions.ImproperlyConfigured: Error loading psycopg2 module: No module named 'psycopg2'
我在堆栈溢出的任何地方都没有发现这个问题。有一点可能与此相关，当我浏览虚拟环境的目录时，我注意到 django 安装在/home/mycode/p3env/lib/python3.5/dist-packages 中，而 psysopg2 安装在/home/mycode/p3env/lib64/python3.5/dist-packages 中。
感谢您的帮助！
> 正如@dentemm所建议的：这个问题是通过将所有 psysopg2 目录从它们在 lib64 目录中的当前位置复制到安装 django 的目录/home/mycode/p3env/lib/python3.5/dist-packages 来解决的。
卸载然后重新安装库真的很有帮助！
(venv($ 点子卸载 psycopg2
(venv($ 点点安装 psycopg2