python - PostgreSQL Psycopg2

Question

我是个编程新手，刚开始学习 Django。我已经能够使用 SQLite 完成工作，但是我在使用 PostgreSQL 时完全停滞不前……我已经在 Stackoverflow 和其他地方查看了几个小时，但一直找不到好的答案。

我的 settings.py 文件:

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql_psycopg2',
        'NAME': 'mydb',
        'USER': 'user',
        'PASSWORD': 'passwd',
        'HOST': 'localhost',
        'PORT': '',
}

在终端中运行的命令:

$ python manage.py validate    

终端输出:

Traceback (most recent call last):
File "manage.py", line 10, in <module>
execute_from_command_line(sys.argv)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/core/management/__init__.py", line 443, in execute_from_command_line
utility.execute()
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/core/management/__init__.py", line 382, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/core/management/base.py", line 196, in run_from_argv
self.execute(*args, **options.__dict__)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/core/management/base.py", line 232, in execute
output = self.handle(*args, **options)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/core/management/base.py", line 371, in handle
return self.handle_noargs(**options)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/core/management/commands/validate.py", line 9, in handle_noargs
self.validate(display_num_errors=True)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/core/management/base.py", line 266, in validate
num_errors = get_validation_errors(s, app)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/core/management/validation.py", line 23, in get_validation_errors
from django.db import models, connection
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/__init__.py", line 40, in <module>
backend = load_backend(connection.settings_dict['ENGINE'])
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/__init__.py", line 34, in __getattr__
return getattr(connections[DEFAULT_DB_ALIAS], item)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/utils.py", line 92, in __getitem__
backend = load_backend(db['ENGINE'])
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/utils.py", line 24, in load_backend
return import_module('.base', backend_name)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/utils/importlib.py", line 35, in import_module
__import__(name)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/backends/postgresql_psycopg2/base.py", line 13, in <module>
from django.db.backends.postgresql_psycopg2.creation import DatabaseCreation
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/backends/postgresql_psycopg2/creation.py", line 1, in <module>
import psycopg2.extensions
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/psycopg2/__init__.py", line 67, in <module>
from psycopg2._psycopg import BINARY, NUMBER, STRING, DATETIME, ROWID
ImportError: dlopen(/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/psycopg2/_psycopg.so, 2): Symbol not found: _PQbackendPID
Referenced from: /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/psycopg2/_psycopg.so
Expected in: dynamic lookup

Answer 1

默认情况下，psycopg2 不会在 OSX 上正确编译。

维护者建议您尽可能使用 Fink 或 Macports 的版本 (http://initd.org/psycopg/install/)。

如果您想/需要从源代码安装，他们提供了这些解决常见问题的链接:http://initd.org/psycopg/articles/2010/11/11/links-about-building-psycopg-mac-os-x/

IIRC，处理此问题的最佳方法是:

• 如果您执行 pip/easy_install(它具有您正在构建的 postgresql 客户端/服务器的所有配置信息)或手动在setup.cfg 如果您手动构建。

• 设置环境变量，为您的 osx 安装明确设置正确的 ARCHFLAGS。有时 python 会尝试在 32 位安装上构建 64 位，反之亦然。

• 新安装有人遇到过 libssl 问题，我从未遇到过这些问题