Python scipy module import error due to missing ._

问题:

I have some troubles with sub-module integrate from scipy in python. I have a 64 bits architecture, and it seems, according to the first lines of the python interpreter (see below) that I am also using a 64 bit build of Python together with Anaconda.

Below is the problem (I just wrote the minimal code to show what's happening)

---

Python 3.4.3 |Anaconda 2.3.0 (64-bit)| (default, Mar  6 2015, 12:06:10) [MSC v.1600 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import scipy
>>> import scipy.integrate
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Users\*********\Anaconda3\lib\site-packages\scipy\integrate\__init__.py", line 55, in <module>
    from .quadrature import *
  File "C:\Users\*********\Anaconda3\lib\site-packages\scipy\integrate\quadrature.py", line 10, in <module>
    from scipy.special.orthogonal import p_roots
  File "C:\Users\*********\Anaconda3\lib\site-packages\scipy\special\__init__.py", line 636, in <module>
    from ._ufuncs import *
ImportError: DLL load failed: Le module spécifié est introuvable.

---

The same happens with import scipy.special

As you can see scipy can be imported, however scipy.integrate generates an error. What is odd is that in the folder ...\lib\site-packages\scipy\special, the ._ufuncs.pyd is appears. Also, I am using scipty regularly for other purposes, and everythings works usually fine.

I am using version 0.18.0 of scipy and pip 1.8.1. I tried to reinstall scipy with conda but this does not seem to change anything.

It seems that the dll cannot be found. I found a few posts on the internet (including one that advises to download a "libmmd.dll" in C:\Windows\SysWOW64) with similar issue, but none seems to work. My guess is that this is still a pb of 32-64 bit compatibility as this is the most common pb with python and I remembered having huge pb when first seting up everything a few months ago.

So, following up the initial question, is there a way to know which version (32 bit or 64 bit) of each package or dll is effectively installed/loaded? Do you have another idea why I get this error message?

Thank you for your answers, this problem is quite frustrating...

回答1:

If you use conda and don't want to install MKL and copy the DLLs as mentioned above, I figured out you can fix this by reinstalling icc_rt package:

conda remove icc_rt --force
conda install icc_rt --no-deps

The icc_rt package has the required DLLs (LIBIFCOREMD.DLL and LIBMMD.DLL).

Below is how I investigated this issue:

I encountered the issue after upgrading my Anaconda to latest version using:

conda update conda
conda update anaconda

I ran Process Monitor while doing import scipy.special to trace which DLL it's trying to load and found out it's libifcoremd.dll.

I then searched my conda pkg cache folder (~/AppData/Local/Continuum/Anaconda3) to find out which package carries this DLL

$ find . -name '*ifcoremd.*'
./pkgs/icc_rt-2017.0.4-h97af966_0/Library/bin/libifcoremd.dll
./pkgs/mkl-11.3.3-1/Library/bin/libifcoremd.dll
./pkgs/mkl-2017.0.1-0/Library/bin/libifcoremd.dll
./pkgs/mkl-2017.0.3-0/Library/bin/libifcoremd.dll

So it's in both mkl and icc_rt packages. But it looks like the latest anaconda (5.2.0) shipped a more recent version of mkl which apparently doesn't have the DLLs anymore:

$ conda list|egrep '^(mkl|icc_rt)\s'
icc_rt                    2017.0.4             h97af966_0
mkl                       2018.0.2                      1

So presumably when conda upgraded my mkl, it deleted the DLLs from my Library\bin folder. So by force reinstalling icc_rt, I got the DLLs back.

回答2:

I solved by the following steps:

1. Install MKL.

2. And for my situation, I checked \scipy\special\_ufuncs.cp36-win_amd64.pyd using Dependency Wakler. Found I miss LIBIFCOREMD.DLL and LIBMMD.DLL. I solved this by install Intel Distribution for Python. Intel Distribution for Python is actually a special version of Python 3.5. And it includes lots of DLL needed. After installing Intel Distribution for Python, go to path_to_Intel_Distribution_for_Python\Library\bin(on my computer is C:\IntelPython3\Library\bin), and copy all folder and files to path_to_your_default_python\Library\bin(on my computer is C:\Anaconda3\Library\bin). (ignore other missing dlls according to this answer).

Then problem solved.

PS. Maybe sometimes files in path_to_Intel_Distribution_for_Python\Library\include\ are also needed?

PPS. You can uninstall Intel Distribution for Python if you no longer need it.

PPPS. A more simple way is to use the wheel. Unofficial Windows Binaries for Python Extension Packages. but I like to use conda update --all to update packages... then everything messed up...

回答3:

It appears the DLL load failed because the module specified is irretrievable?

Please see:

ImportError: DLL load failed: %1 is not a valid Win32 application. But the DLL's are there