导入错误：没有安装了 2 个版本的 Python 的名为“flask_sqlalchemy”的模块

Question

尝试使用以下导入运行文件：

 from flask_sqlalchemy import sqlalchemy
from sqlalchemy import create_engine
from sqlalchemy.orm import scoped_session, sessionmaker

收到以下错误：

 ImportError: No module named 'flask_sqlalchemy'

SQLAlchemy 已安装。尽管如此，我还是尝试重新安装到将要使用它的目录中。我懂了：

 The directory '/Users/_/Library/Caches/pip/http' or its parent directory is not owned by the current user and the cache has been disabled. Please check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag.
The directory '/Users/_/Library/Caches/pip' or its parent directory is not owned by the current user and caching wheels has been disabled. check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag.
Requirement already satisfied: Flask-SQLAlchemy in /Library/Python/2.7/site-packages (2.3.2)
Requirement already satisfied: Flask>=0.10 in /Library/Python/2.7/site-packages (from Flask-SQLAlchemy) (1.0.2)
Requirement already satisfied: SQLAlchemy>=0.8.0 in /Library/Python/2.7/site-packages (from Flask-SQLAlchemy) (1.2.10)
Requirement already satisfied: Jinja2>=2.10 in /Library/Python/2.7/site-packages (from Flask>=0.10->Flask-SQLAlchemy) (2.10)
Requirement already satisfied: itsdangerous>=0.24 in /Library/Python/2.7/site-packages (from Flask>=0.10->Flask-SQLAlchemy) (0.24)
Requirement already satisfied: Werkzeug>=0.14 in /Library/Python/2.7/site-packages (from Flask>=0.10->Flask-SQLAlchemy) (0.14.1)
Requirement already satisfied: click>=5.1 in /Library/Python/2.7/site-packages (from Flask>=0.10->Flask-SQLAlchemy) (6.7)
Requirement already satisfied: MarkupSafe>=0.23 in /Library/Python/2.7/site-packages (from Jinja2>=2.10->Flask>=0.10->Flask-SQLAlchemy) (1.0)

关于我不拥有该目录的说法是不正确的。我是这台机器上唯一的人。我拥有一切。

无论如何，我回去重新运行文件并得到相同的错误消息。因此，它已安装，但未安装，或者至少对我不可用。

当我注释掉其中一个导入语句时看到的一条错误消息如下所示：

 File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/sqlalchemy/engine/strategies.py

我不知道如何解决这个问题并启动和运行 SQLAlchemy。我已经在上面烧了 1.5 多个小时。列出的最后一个错误表明有 2 个版本的 python 可能与它有关。

您对补救措施的想法将不胜感激。

原文由 Ryan 发布，翻译遵循 CC BY-SA 4.0 许可协议

Answer 1

最终，我在发布上述问题后解决了这个问题。

修复是通过 Anaconda 运行所有包更新和安装，并在 Spyder 中完成我的工作。

吸取的教训很简单：一旦您开始使用 Anaconda 作为所有 Python 的首选环境，所有更新（通过 conda 安装或 pip 进行）将默认由 Anaconda 编排并放置在您的系统中。

原文由 Ryan 发布，翻译遵循 CC BY-SA 4.0 许可协议

Answer 2

我认为您的 pip 和 python 版本不匹配。检查你的 pip 版本 pip –version ，如果它是 pip3

你可以试试这个

sudo apt-get install python3-sqlalchemy

这应该工作。

 ~$ python3

>>import sqlalchemy

原文由 Jadhav Gaurav 发布，翻译遵循 CC BY-SA 4.0 许可协议