【发布时间】：2015-03-06 15:59:17
【问题描述】：
所以如果我用python 启动Python 2.7 的shell，然后运行import psycopg2，我不会收到任何错误。但是，如果我尝试在 Python 3.4 的 shell 中运行 import psycopg2，我会得到：ImportError: No module named 'psycopg2'。另一方面，导入 django 在两个 shell 上都可以正常工作（使用 pip3 安装后）。
其次，如果我运行python3 manage.py runserver，我会收到一个错误（见下文），而如果我只使用python，我不会。我认为这是因为我描述的第一个问题，但我不确定（对不起，如果这是一个愚蠢的问题，我对 Django 真的很陌生 - 试图通过教程）。
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/backends/postgresql_psycopg2/base.py", line 23, 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 10, in < module >
execute_from_command_line(sys.argv)
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/core/management/__init__.py", line 385, in execute_from_command_line
utility.execute()
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/core/management/__init__.py", line 354, in execute
django.setup()
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/__init__.py", line 21, in setup
apps.populate(settings.INSTALLED_APPS)
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/apps/registry.py", line 108, in populate
app_config.import_models(all_models)
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/apps/config.py", line 202, in import_models
self.models_module = import_module(models_module_name)
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/importlib/__init__.py", line 109, in import_module
return _bootstrap._gcd_import(name[level: ], package, level)
File "<frozen importlib._bootstrap>", line 2254, in _gcd_import
File "<frozen importlib._bootstrap>", line 2237, in _find_and_load
File "<frozen importlib._bootstrap>", line 2226, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 1200, in _load_unlocked
File "<frozen importlib._bootstrap>", line 1129, in _exec
File "<frozen importlib._bootstrap>", line 1471, in exec_module
File "<frozen importlib._bootstrap>", line 321, in _call_with_frames_removed
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/contrib/auth/models.py", line 40, in < module >
class Permission(models.Model):
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/models/base.py", line 122, in __new__
new_class.add_to_class('_meta', Options(meta, * * kwargs))
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/models/base.py", line 297, in add_to_class
value.contribute_to_class(cls, name)
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/models/options.py", line 166, in contribute_to_class
self.db_table = truncate_name(self.db_table, connection.ops.max_name_length())
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/__init__.py", line 40, in __getattr__
return getattr(connections[DEFAULT_DB_ALIAS], item)
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/utils.py", line 242, in __getitem__
backend = load_backend(db['ENGINE'])
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/utils.py", line 108, in load_backend
return import_module('%s.base' % backend_name)
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/importlib/__init__.py", line 109, in import_module
return _bootstrap._gcd_import(name[level: ], package, level)
File "<frozen importlib._bootstrap>", line 2254, in _gcd_import
File "<frozen importlib._bootstrap>", line 2237, in _find_and_load
File "<frozen importlib._bootstrap>", line 2226, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 1200, in _load_unlocked
File "<frozen importlib._bootstrap>", line 1129, in _exec
File "<frozen importlib._bootstrap>", line 1471, in exec_module
File "<frozen importlib._bootstrap>", line 321, in _call_with_frames_removed
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/backends/postgresql_psycopg2/base.py", line 27, in < module >
raise ImproperlyConfigured("Error loading psycopg2 module: %s" % e)
django.core.exceptions.ImproperlyConfigured: Error loading psycopg2 module: No module named 'psycopg2'
我能做些什么来解决它？
此外，我对 Django 的整个 Python 2 vs 3 业务感到非常困惑（如果这是一个非常基本的问题，再次抱歉）。当您运行django-admin.py startproject theproject 时，如何指定要与 Django 一起使用的 Python 版本？是否就像在 Python 3 中编写代码并使用 python3 而不是 python 运行所有内容一样简单？
【问题讨论】：
-
您已经运行
pip3 install psycopg2了吗？有没有报错？
标签： python django postgresql python-2.7 psycopg2