1
因此，如果我用python启动Python 2.7的shell并运行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，则得到：ImportError: No module named 'psycopg2'。另一方面，导入Django可以在两个shell上正常工作（使用pip3进行安装后）。其次，如果我运行python3 manage.py runserver，则出现错误（请参阅下文），而如果我仅使用python，则会出错。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非常陌生 - 试图通过本教程）。使用PostgreSQL（psycopg2）和Django运行Python 3.4时出错
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'
我该怎么办才能修复它？
此外，我对Django的整个Python 2 vs 3业务感到困惑（再次抱歉，如果这是一个非常基本的问题）。当你运行django-admin.py startproject theproject时，你如何指定你想用Django的哪个版本的Python？是否就像在Python 3中编写代码并使用python3而不是python运行一样简单？
你已经运行'pip3安装psycopg2'？它有任何错误吗？ – Alasdair