Importing the multiarray numpy extension module failed

[pfmoore]

I'm trying to install numpy 1.13.0. My machine is Windows 7, and my Python install is 64-bit Python 3.6.0. I previously had an older version of numpy installed (from Christoph Gohlke's site) but I uninstalled that. I also had a couple of Anaconda installations, but I also uninstalled them. However, when I try to import numpy, I get the above error:

PS 11:46 {00:04.053} D:\experiments                                                                                                                 
>pip install --no-cache numpy                                                                                                                       
Collecting numpy                                                                                                                                    
  Downloading numpy-1.13.0-cp36-none-win_amd64.whl (7.8MB)                                                                                          
    100% |████████████████████████████████| 7.8MB 541kB/s                                                                                           
Installing collected packages: numpy                                                                                                                
Successfully installed numpy-1.13.0                                                                                                                 
PS 11:46 {00:18.096} D:\experiments                                                                                                                 
>python                                                                                                                                             
Python 3.6.0 (v3.6.0:41df79263a11, Dec 23 2016, 08:06:12) [MSC v.1900 64 bit (AMD64)] on win32                                                      
Type "help", "copyright", "credits" or "license" for more information.                                                                              
>>> import numpy                                                                                                                                    
Traceback (most recent call last):                                                                                                                  
  File "C:\Users\UK03306\AppData\Local\Programs\Python\Python36\lib\site-packages\numpy\core\__init__.py", line 16, in <module>                     
    from . import multiarray                                                                                                                        
ImportError: DLL load failed: The specified procedure could not be found.                                                                           
                                                                                                                                                    
During handling of the above exception, another exception occurred:                                                                                 
                                                                                                                                                    
Traceback (most recent call last):                                                                                                                  
  File "<stdin>", line 1, in <module>                                                                                                               
  File "C:\Users\UK03306\AppData\Local\Programs\Python\Python36\lib\site-packages\numpy\__init__.py", line 142, in <module>                         
    from . import add_newdocs                                                                                                                       
  File "C:\Users\UK03306\AppData\Local\Programs\Python\Python36\lib\site-packages\numpy\add_newdocs.py", line 13, in <module>                       
    from numpy.lib import add_newdoc                                                                                                                
  File "C:\Users\UK03306\AppData\Local\Programs\Python\Python36\lib\site-packages\numpy\lib\__init__.py", line 8, in <module>                       
    from .type_check import *                                                                                                                       
  File "C:\Users\UK03306\AppData\Local\Programs\Python\Python36\lib\site-packages\numpy\lib\type_check.py", line 11, in <module>                    
    import numpy.core.numeric as _nx                                                                                                                
  File "C:\Users\UK03306\AppData\Local\Programs\Python\Python36\lib\site-packages\numpy\core\__init__.py", line 26, in <module>                     
    raise ImportError(msg)                                                                                                                          
ImportError:                                                                                                                                        
Importing the multiarray numpy extension module failed.  Most                                                                                       
likely you are trying to import a failed build of numpy.                                                                                            
If you're working with a numpy git repo, try `git clean -xdf` (removes all                                                                          
files not under version control).  Otherwise reinstall numpy.                                                                                       

I've checked every other copy of Python on my PC and none of them have numpy installed. I really don't want to uninstall and reinstall my whole Python installation, as there's a lot of packages installed that I'd have to reinstall. None of the other packages, as far as I can tell, are likely to affect numpy (or if they might, they are at the latest version anyway).

What options do I have to work out what's wrong here before I have to clear out every Python install on my machine and do a full reinstall?

[rgommers]

No, shouldn't be affected by other packages. I assume you've checked there's nothing weird in your PATH or PYTHONPATH? And when you say "uninstalled them", did you go into your site-packages and did (a Windows equivalent of )rm -rf numpy? Could be some leftover from the @cgohlke package maybe.

@matthew-brett ping

[pfmoore]

I did pip install numpy. There's nothing in site-packages with "numpy" in the name after doing so. I wondered about the possibility that it was because I had previously used @cgohlke's builds, but the uninstalls seem to have happened cleanly.

There's nothing obvious that I can see on PATH and I have no PYTHONPATH.

After a bit more playing with ctypes there definitely seems to be something wrong with multiarray:

>>> ctypes.cdll.LoadLibrary(r'C:\users\uk03306\appdata\local\programs\python\python36\lib\site-packages\numpy\core\multiarray.cp36-win_amd64.pyd')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Users\UK03306\AppData\Local\Programs\Python\Python36\lib\ctypes\__init__.py", line 422, in LoadLibrary
    return self._dlltype(name)
  File "C:\Users\UK03306\AppData\Local\Programs\Python\Python36\lib\ctypes\__init__.py", line 344, in __init__
    self._handle = _dlopen(self._name, mode)
OSError: [WinError 126] The specified module could not be found
>>> ctypes.cdll.LoadLibrary(r'C:\users\uk03306\appdata\local\programs\python\python36\lib\site-packages\numpy\core\umath.cp36-win_amd64.pyd')
<CDLL 'C:\users\uk03306\appdata\local\programs\python\python36\lib\site-packages\numpy\core\umath.cp36-win_amd64.pyd', handle 7fecc110000 at 0x2789eb8>
>>>

[pfmoore]

Doing some digging with dependency walker, it looks like some files might be failing to load (things like API-MS-WIN-CORE-WINRT-ERROR-L1-1-0.DLL).

A search of the net shows that these are related to Windows 8 only libraries. I assume these have been linked in accidentally, and numpy isn't desupporting Windows 7?

See https://github.com/dotnet/coreclr/issues/65 and https://answers.microsoft.com/en-us/windows/forum/windows_10-files/missing-api-ms-win-core-dlls/d99d1368-0f92-43db-bbdb-7d080f1f96e9 for a couple of links that I found while researching this issue.

As a short term fix, I've reverted to numpy 1.12.1

[pfmoore]

I just checked with a colleague. He has the 32-bit build and that seems to work fine. So it may be something specific to the 64-bit binary.

[cgohlke]

This is probably Python issue 29943. Extensions built with Python 3.6.1 won't work on 3.6.0.

[matthew-brett]

@cgohlke - good suggestion. From that bug, we should rebuild the numpy wheel with Python 3.6.0. Appveyor defaults to 3.6.1 : https://www.appveyor.com/docs/build-environment/#python

[matthew-brett]

Indeed, the release build was on 3.6.1 : https://ci.appveyor.com/project/matthew-brett/numpy-wheels-jc1cl/build/1.0.50/job/71fmdc5c41j4r9y6#L105

[njsmith]

That bug should only affect packages that reference PySlices_GetIndicesEx, though, and can be diagnosed by checking if the resulting binary refers toPySlice_AdjustIndices. I thought numpy wasn't affected.

[pfmoore]

I've just tested on my home PC, which has Python 3.6.1, and numpy 1.13 works fine there. However, my home PC is also Windows 10, and has a lot of other differences, so it's not a perfect test. I'll upgrade my work PC to 3.6.1 tomorrow, and test there.

[matthew-brett]

On my test machine, I installed numpy in a virtualenv for Python.org 3.6.0, got the crash, then installed Python 3.6.1 and didn't get the crash.

[pfmoore]

I can confirm that upgrading to 3.6.1 fixes my issue on the machine I originally had the problem with. Personally, I'm OK for this issue to be closed with "upgrade to 3.6.1" as the resolution, but I'll leave it to you to close it in case you'd prefer to fix the binary to support 3.6.0.

[charris]

@matthew-brett I'm going to make a 1.13.1 soon. Are you going to make any modifications to the build?

[matthew-brett]

@charris - I guess we should build on 3.6.0. I don't think there's any way to do that with Appveyor and the stock Pythons, so we will need to use Conda.

I was experimenting with building openblas this time, but that may take a little while to finish up - say a week?

[njsmith]

Can someone confirm whether the bad numpy Windows wheels contain a reference to the symbol PySlice_AdjustIndices? If they do then the problem is not restricted to Windows, so we'll need to watch out for that, but at least it's known and will be fixed in the 3.6.2 which is coming out imminently. If not then something else is going on, possibly a previously unknown 3.6.1 abi break that we should report upstream urgently.

Cc @zooba