导入OrbitalPy时出现_cext模块缺失错误求助

问题重现 #

运行OrbitalPy官方示例代码时触发kiwisolver的_cext模块DLL加载失败，报错信息如下：

C:\Users\xxx\Desktop>py molniya.py
Traceback (most recent call last):
  File "C:\Users\xxx\Desktop\molniya.py", line 4, in <module>
    from orbital import earth, KeplerianElements, Maneuver, plot, plot3d
  File "C:\Users\xxx\AppData\Local\Programs\Python\Python311\Lib\site-packages\orbital\__init__.py", line 8, in <module>
    from .plotting import *
  File "C:\Users\xxx\AppData\Local\Programs\Python\Python311\Lib\site-packages\orbital\plotting.py", line 9, in <module>
    import matplotlib as mpl
  File "C:\Users\xxx\AppData\Local\Programs\Python\Python311\Lib\site-packages\matplotlib\__init__.py", line 246, in <module>
    _check_versions()
  File "C:\Users\xxx\AppData\Local\Programs\Python\Python311\Lib\site-packages\matplotlib\__init__.py", line 240, in _check_versions
    module = importlib.import_module(modname)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\xxx\AppData\Local\Programs\Python\Python311\Lib\importlib\__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\xxx\AppData\Local\Programs\Python\Python311\Lib\site-packages\kiwisolver\__init__.py", line 8, in <module>
    from ._cext import (
ImportError: DLL load failed while importing _cext: The specified module could not be found.

使用的示例代码：

from numpy import radians
from scipy.constants import kilo

from orbital import earth, KeplerianElements, Maneuver, plot, plot3d

from orbital import earth_sidereal_day
molniya = KeplerianElements.with_period(
    earth_sidereal_day / 2, e=0.741, i=radians(63.4), arg_pe=radians(270),
    body=earth)

plot3d(molniya)

解决方案 #

按顺序尝试以下步骤：

• 安装兼容版本的kiwisolver
  卸载当前版本，安装适配Python3.11的指定版本：

  pip uninstall kiwisolver -y
  pip install kiwisolver==1.4.4
  

• 安装微软VC++运行库
  系统缺失VC++ Redistributable是DLL加载失败的常见原因，下载对应系统位数（x64/x86）的最新VC++运行库安装包，安装后重启电脑。

• 使用conda创建隔离环境
  若使用conda，通过新环境避免依赖冲突：

  conda create -n orbital_env python=3.10 -y
  conda activate orbital_env
  pip install orbitalpy
  

  在此环境中运行示例代码，依赖会自动适配版本。

• 检查并添加PATH环境变量
  将Python的Scripts目录和kiwisolver所在目录添加到系统PATH：

  • 路径示例：C:\Users\xxx\AppData\Local\Programs\Python\Python311\Scripts
  • 路径示例：C:\Users\xxx\AppData\Local\Programs\Python\Python311\Lib\site-packages\kiwisolver
    添加后重启终端再运行代码。

内容的提问来源于stack exchange，提问作者EarthAndMoon