import pystan._api failed:ImportError: DLL load failed: The specified module could not be found

VanodyaPerera picture VanodyaPerera · Feb 25, 2020 · Viewed 7.6k times · Source

I have installed python 3.7 and want to do some forecasting using fbprophet (https://facebook.github.io/prophet/docs/installation.html#python)

But I get this error when installing the package using the command (pip install fbprophet)

import pystan
  File "e:\repos\usf\venv\lib\site-packages\pystan\__init__.py", line 9, in <module>
    from pystan.api import stanc, stan
  File "e:\repos\usf\venv\lib\site-packages\pystan\api.py", line 13, in <module>
    import pystan._api  # stanc wrapper
ImportError: DLL load failed: The specified module could not be found.

I have done some research and got to know that this is possible with conda. But I am looking for a solution without using conda.

Thanks in advance.

Answer

Akalanka Weerasooriya picture Akalanka Weerasooriya · Nov 6, 2020

It says in the Pystan documentation that configuring a C++ compiler can be challenging on Windows. Following approach worked for me to install Pystan 2.17.1 and FBProphet 0.6:

  1. Install C++ compiler, mingw-w64 (http://mingw-w64.org/doku.php/download) -> I selected this one https://sourceforge.net/projects/mingw-w64/files/

  2. Add C:<MinGW_w64 installation directory>\bin to the PATH environment variable

  3. Create a distutils.cfg file with the following contents in the folder \Lib\distutils in Python install directory (in venv):

    [build] compiler=mingw32

    [build_ext] compiler=mingw32

  4. pip install numpy cython

  5. pip install pystan==2.17.1

  6. Verify the Pystan installation (https://pystan.readthedocs.io/en/latest/windows.html)

  7. pip install fbprophet==0.6