How to resolve "ImportError: DLL load failed:" on Python?

Question

Recently I start to get ImportError: DLL load failed: error when I import different libraries (for example scikit-learn or scipy and some others).

My assumptions is that I have broken something when I was trying to pip install opencv.

So, my question is how to resolve this problem that seems to be not library specific?

Can I pip install DLL or something like that? Can I just reinstall the whole Python? I am working on Windows. My version of Python is Python 2.7.10 :: Anaconda 2.3.0 (64-bit).

ADDED

If I print sys.path I get this:

['',
 'C:\\Anaconda\\Scripts',
 'C:\\Anaconda\\python27.zip',
 'C:\\Anaconda\\DLLs',
 'C:\\Anaconda\\lib',
 'C:\\Anaconda\\lib\\plat-win',
 'C:\\Anaconda\\lib\\lib-tk',
 'C:\\Anaconda',
 'C:\\Anaconda\\lib\\site-packages',
 'C:\\Anaconda\\lib\\site-packages\\Sphinx-1.3.1-py2.7.egg',
 'C:\\Anaconda\\lib\\site-packages\\cryptography-0.9.1-py2.7-win-amd64.egg',
 'C:\\Panda3D-1.9.2-x64',
 'C:\\Panda3D-1.9.2-x64\\bin',
 'C:\\Anaconda\\lib\\site-packages\\win32',
 'C:\\Anaconda\\lib\\site-packages\\win32\\lib',
 'C:\\Anaconda\\lib\\site-packages\\Pythonwin',
 'C:\\Anaconda\\lib\\site-packages\\setuptools-17.1.1-py2.7.egg',
 'C:\\Anaconda\\lib\\site-packages\\IPython\\extensions',
 'C:\\Users\\myname\\.ipython']

What worries me is that there is a mixture of 32 and 64 versions. Another thing, maybe I just have different Pythons and I just need to call the proper one?

Answer 1

If anyone comes across this issue in Python > 3.8 with Windows, dll's are only loaded from trusted locations https://docs.python.org/3/whatsnew/3.8.html#ctypes This can be fixed by adding the dll path using os.add_dll_directory("PATH_TO_DLL")

Answer 2

I have managed to resolve the problem by reinstalling Python. First, I have uninstalled Python (like any other program in Windows). Then I have installed Anaconda distribution of Python. The problem is not present anymore.

Answer 3

I just encountered this exact problem and was struggling to solve it. I tried to reinstall anaconda, I reinstalled the relevant packages, I changed my environment - BUT NOTHING WORKED! eventually, after few hours, I managed to solve this problem with some few easy steps as described here :)

just type in the command line (one code-line at a time): conda install numpy then, conda install scipy then, pip install -U seaborn then, pip install -U numpy and finally, pip install -U scipy

That's it :) - it is now working! (it also fixed the error for all of the other libraries as well, such as sklearn, matplotlib etc.)