问题描述
pip 说 minizinc 已经安装，但是当我尝试在代码中调用它时，它给我错误说它没有安装。
(backend) bash-3.2$ python
Python 3.8.3 (default,Jul 2 2020,11:26:31)
[Clang 10.0.0 ] :: Anaconda,Inc. on darwin
Type "help","copyright","credits" or "license" for more information.
>>> from minizinc import Instance,Model,Solver
/Users/miranda/.local/share/virtualenvs/backend-BjqhdW2P/lib/python3.8/site-packages/minizinc/__init__.py:25: RuntimeWarning: MiniZinc was not found on the system. No default driver Could be initialised.
warnings.warn(
Traceback (most recent call last):
File "<stdin>",line 1,in <module>
ImportError: cannot import name 'Instance' from 'minizinc' (/Users/miranda/.local/share/virtualenvs/backend-BjqhdW2P/lib/python3.8/site-packages/minizinc/__init__.py)
>>> exit()
(backend) bash-3.2$ pip install minizinc
Requirement already satisfied: minizinc in /Users/miranda/.local/share/virtualenvs/backend-BjqhdW2P/lib/python3.8/site-packages (0.4.2)
(backend) bash-3.2$ python3 -m pip install minizinc
Requirement already satisfied: minizinc in /Users/miranda/.local/share/virtualenvs/backend-BjqhdW2P/lib/python3.8/site-packages (0.4.2)
(backend) bash-3.2$ python -m pip install minizinc
Requirement already satisfied: minizinc in /Users/miranda/.local/share/virtualenvs/backend-BjqhdW2P/lib/python3.8/site-packages (0.4.2)
解决方法
如 MiniZinc Python 的 "Getting Started" 页面所述。 MiniZinc Python 与 MiniZinc 本身不同，它只是 Python 与 MiniZinc 的连接。
这意味着在您可以使用 MiniZinc Python 之前，您还必须安装 MiniZinc 包。这就是错误试图告诉你的。该捆绑包可在 MiniZinc website 上找到。
请注意，安装后 MiniZinc Python 会在您的计算机上查找 minizinc 可执行文件，只要您在 Python 中import minizinc。如果您没有在通常的位置安装 MiniZinc，那么您可能需要将 PATH 环境变量附加到 minizinc 所在的目录中才能使其工作。