158
votes

I'm trying to run this program

import cv2
import time

cv.NamedWindow("camera", 1)

capture = cv.CaptureFromCAM(0)

while True:
    img = cv.QueryFrame(capture)
    cv.ShowImage("camera", img)
    if cv.WaitKey(10) == 27:
        break
cv.DestroyAllWindows()

But I'm having a problem with numpy, I'm using pyschopy along with opencv. The problem I keep getting is this error report:

RuntimeError: module compiled against API version 7 but this version of numpy is 6

Traceback (most recent call last):

File "C:\Users\John\Documents\EyeTracking\Programs\GetImage.py", line 1, in

import cv2

ImportError: numpy.core.multiarray failed to import

I have numpy-1.6.1-py2.7 in the psychopy folder, I'm just confused as to what is wrong?

Edit (Deleted Answer)

The following command

pip install -U numpy 

helps solving the problem: could not load numpy.core.multiarray.

30
I get the same error message and I have numpy-1.9.2 installed.tommy.carstensen
In my case, I was using Anaconda distribution on Windows, and running conda update pythontwo times (once to update conda, and again to update python to 2.7.13) fixed the problem.Jason O.
Running pip install opencv-python==3.4.2.17 numpy==1.14.5 worked for meMarkus Weber
I get the same error with NumPy 1.16.3, python 3.7 and latest macOS, upgrade to 1.16.4 solve the problem.nngeek

30 Answers

157
votes

I was getting the same error and was able to solve it by updating my numpy installation to 1.8.0:

pip install -U numpy
32
votes

In the case that

pip install -U numpy 

doesn't work (even with sudo), you may want to make sure you're using the right version of numpy. I had the same "numpy.core.multiarray failed to import" issue, but it was because I had 1.6 installed for the version of Python I was using, even though I kept installing 1.8 and assumed it was installing in the right directory.

I found the bad numpy version by using the following command in my Mac terminal:

python -c "import numpy;print(numpy.__version__);print(numpy.__file__)";

This command gave me the version and location of numpy that I was using (turned out it was 1.6.2). I went to this location and manually replaced it with the numpy folder for 1.8, which resolved my "numpy.core.multiarray failed to import" issue. Hopefully someone finds this useful!

Note: For the command, use double underscore before and after 'version' and 'file'

20
votes

If you want a specific version:

pip install numpy==1.8
17
votes

If you are using python3, the following command fixes the problem in macos.

python3 -m pip install numpy -I

15
votes

Try sudo pip install numpy --upgrade --ignore-installed.

It work in Mac OS 10.11.

You should close The 'Rootless' if above shell isn't work.

11
votes
pip install opencv-python==3.4.2.17 numpy==1.14.5

done the job for me!

10
votes

I had the same error message, after trying some of the suggested solutions without success, I found that I needed to run:

pip uninstall numpy

multiple times. Each time several different files were flagged for removal, from different versions of numpy that had accumulated on my system.

Once there was nothing left to uninstall, it was a matter of

pip install numpy

Hope this helps someone!

9
votes

you may need upgrade pip, it works for me

pip install --upgrade pip
pip install -U numpy
7
votes

OK so I found a solution that worked for me when trying to get OpenCV to work with Python 3.9 on Windows 10.

This is a known issue for Windows versions past v2004.

In short, the version of NumPY that you need is v1.19.3:

pip uninstall numpy

pip install numpy==1.19.3

Or to do this in one command, use the --force-reinstall flag for pip:

pip install --force-reinstall numpy==1.19.3
5
votes

for me this error came up when installing pygrib with conda and importing it.

conda install -c conda-forge numpy

solved the problem.

4
votes

In my case this problem was because I'd two python installations (2.7 and 3.5) and pip was installing numpy in the 3.5 python directory only, irrespective of which pip version I used.

I solved the problem by explicitly specifying the target install directory as such:

pip install --target c:\apps\python-2.7\Lib\site-packages numpy
3
votes

I don't really understand this error but I solved this error with below.

pip install -U opencv-python

Hope it was useful!

3
votes

I was getting the same error and the problem was solved by updating my numpy installation from 1.7.1 to 1.12.1

pip install -U numpy

The followings were my cmd sequence when the error was occurred, slightly different from the above:

$ python

Python 2.7.12 |Anaconda 4.2.0 (x86_64)| (default, Jul  2 2016, 17:43:17) 

[GCC 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.11.00)] on darwin

Type "help", "copyright", "credits" or "license" for more information.

Anaconda is brought to you by Continuum Analytics.

Please check out: http://continuum.io/thanks and https://anaconda.org

>>> import cv2

>>> import numpy as np

>>> from matplotlib import pyplot as plt
3
votes
pip install numpy==1.19.3

this did the job for me.

2
votes

After having a nightmare using the pip install -U numpy several months ago, I gave up. I went through installing CV2s and opencv without success.

I was using numpy ver 1.9.1 on python34 and the upgrade just kept stalling on on 1.9.

So I went to https://pypi.python.org/pypi/numpy and discovered the latest numpy version for my python3.4.

I downloaded the .whl file and copied it into the folder containing my python installation, C:\Python34, in my case.

I then ran pip intall on the file name and I can now import cv2 problem free.

Make sure you close down python before you start, obvious but essential

2
votes

It worked for me. So you can try following command

$ pip install numpy -I
2
votes

In my case installing from apt solved my problem.

You can try uninstall it from pip and install from apt (if you are using ubuntu etc.)

pip3 uninstall numpy
sudo apt-get install python3-numpy
2
votes

run this codes worked for me, seems to be issue with version.

pip uninstall numpy

pip install numpy==1.19.3
2
votes

I used Anaconda environment and had the same issue. I tried all the aforementioned approaches and, alas, it didn't help me. Accumulated the suggestions, here the way which helped me:

  1. Delete all NumPy folders in the virtual environment or in the system if you don't use a virtual environment, for example in my case:

    ~/home/anaconda3/envs//lib/python/site-packages/numpy

    ~/home/anaconda3/envs//lib/python/site-packages/numpy.libs

    ~/home/anaconda3/envs//lib/python/site-packages/numpy-.dist-info

  2. Install new Numpy with:

    pip install numpy -U

Hope, it could help in the same case

2
votes

All these varied answers suggest that many different problems appear as ImportError: numpy.core.multiarray failed to import.

==> So look for more error information before the stack traceback

E.g. steps to reproduce one such problem (these steps worked fine until numpy 1.20 was released):

# set up a virtualenv
pyenv virtualenv 3.8.7 pip-issue-9542
pyenv local pip-issue-9542

# update pip, setuptools
pip install -U pip setuptools

# install 2 pips
pip install --no-cache-dir numpy==1.19.5 cvxpy==1.1.3

# try to load cvxpy
python -c 'import cvxpy'

Output:

RuntimeError: module compiled against API version 0xe but this version of numpy is 0xd
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/usr/local/var/pyenv/versions/pip-issue-9542/lib/python3.8/site-packages/cvxpy/__init__.py", line 18, in <module>
    from cvxpy.atoms import *
  File "/usr/local/var/pyenv/versions/pip-issue-9542/lib/python3.8/site-packages/cvxpy/atoms/__init__.py", line 20, in <module>
    from cvxpy.atoms.geo_mean import geo_mean
  File "/usr/local/var/pyenv/versions/pip-issue-9542/lib/python3.8/site-packages/cvxpy/atoms/geo_mean.py", line 20, in <module>
    from cvxpy.utilities.power_tools import (fracify, decompose, approx_error, lower_bound,
  File "/usr/local/var/pyenv/versions/pip-issue-9542/lib/python3.8/site-packages/cvxpy/utilities/power_tools.py", line 18, in <module>
    from cvxpy.atoms.affine.reshape import reshape
  File "/usr/local/var/pyenv/versions/pip-issue-9542/lib/python3.8/site-packages/cvxpy/atoms/affine/reshape.py", line 18, in <module>
    from cvxpy.atoms.affine.hstack import hstack
  File "/usr/local/var/pyenv/versions/pip-issue-9542/lib/python3.8/site-packages/cvxpy/atoms/affine/hstack.py", line 18, in <module>
    from cvxpy.atoms.affine.affine_atom import AffAtom
  File "/usr/local/var/pyenv/versions/pip-issue-9542/lib/python3.8/site-packages/cvxpy/atoms/affine/affine_atom.py", line 22, in <module>
    from cvxpy.cvxcore.python import canonInterface
  File "/usr/local/var/pyenv/versions/pip-issue-9542/lib/python3.8/site-packages/cvxpy/cvxcore/python/__init__.py", line 3, in <module>
    import _cvxcore
ImportError: numpy.core.multiarray failed to import

The important clue is RuntimeError: module compiled against API version 0xe but this version of numpy is 0xd.

Searching on that can get you to pip issue 9542 and cvxpy issue 1229 which explain what went wrong.

The workarounds in this case are to (a) update to cvxpy>=1.1.10, or (b) update to numpy>=1.20, or (c) update both. You'll have to cope with library changes since the original environment is not reproducible without diving into pip's --no-build-isolation world.

1
votes

I had the same error after installing python and opencv in my D: drive (C: runs on a SSD). The problem seemed to be that my execution path was inside the numpy folder. You can check if that's the issue with this code :

import numpy
numpy.version.version

In case it retrieves any error related to the execution path, execute your original code from elsewhere. That solved the could not load numpy.core.multiarray error for me

1
votes

I Had the same error occurring as I was using the numpy version suggested by the requirements.txt in the repo. When I tried to 'import pandas as pd' this error occurred. Then the solution was to upgrade numpy version to 1.15.2 as the version suggested in the requirements was mismatching with pandas. I uninstalled the existing numpy version with pip and reinstalled the new version.

pip install numpy==1.15.2 

Hope this helps someone

1
votes

I had the same issue, and here's how it's solved in my case.

I tried pip install -U numpy but it didn't upgrade numpy, but conda install worked for me

ImportError: numpy.core.multiarray failed to import
admin@MacBook-Air$ pip install -U numpy
Requirement already up-to-date: numpy in /Users/admin/anaconda/lib/python2.7/site-packages
admin@MacBook-Air$ python
Python 2.7.12 |Anaconda 2.4.0 (x86_64)| (default, Jul  2 2016, 17:43:17) 
[GCC 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.11.00)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
Anaconda is brought to you by Continuum Analytics.
Please check out: http://continuum.io/thanks and https://anaconda.org
>>> import numpy
numpy.version.version
>>> numpy.version.version
'1.7.1'
>>> exit
Use exit() or Ctrl-D (i.e. EOF) to exit
>>> 
admin@MacBook-Air$ 
admin@MacBook-Air$ conda install numpy
Fetching package metadata .......
Solving package specifications: ..........

Package plan for installation in environment /Users/admin/anaconda:

The following packages will be downloaded:

    package                    |            build
    ---------------------------|-----------------
    scikit-learn-0.18.1        |      np111py27_0         4.9 MB

The following packages will be UPDATED:

    numexpr:      2.3.0-np17py27_0  --> 2.6.1-np111py27_1 
    numpy:        1.7.1-py27_2      --> 1.11.2-py27_0     
    scikit-learn: 0.14.1-np17py27_1 --> 0.18.1-np111py27_0
    scipy:        0.13.2-np17py27_1 --> 0.18.1-np111py27_0

Proceed ([y]/n)? y

Fetching packages ...
scikit-learn-0 100% |#################################################################| Time: 0:00:16 312.60 kB/s
Extracting packages ...
[      COMPLETE      ]|####################################################################################| 100%
Unlinking packages ...
[      COMPLETE      ]|####################################################################################| 100%
Linking packages ...
[      COMPLETE      ]|####################################################################################| 100%
1
votes

Tilde folders

In the event pip uninstall numpy and reinstallation of Numpy does not work. Review your site-packages folder for sub-folders beginning with a tilde ~

These folders relate to pip installations that got mangled and the installation was aborted part way through. The tilde folders were only ever meant to be tmp folders but ended up becoming permanent. In my case there was a file called ~mpy which was a mangled legacy Numpy folder. This led to compatibility issues and ImportErrors.

These mangled folders can safely be deleted, for further details see this answer

1
votes

I was able to solve the problem by updating my python to 3.8. I am using Macbook Air with Catalina. The problem started for me after updating TensorFlow. After updating it, the error doesn't disappear after I uninstalled and installed numpy several times.

Finally, I downloaded the python3.8 package from python website and installed. Then I installed numpy and it worked.

0
votes

The same error came for me. The problem is that you might have created a file called numpy.py. This file might coincide with numpy library. So, delete that numpy.py file and the problem gets solved.

0
votes

This helped me

sudo pip3 install --upgrade --target=/home/<username>/.local/lib/python3.6/site-packages numpy
0
votes

For me it was a two part. First:

pip uninstall numpy

Then @Oli Blum answer (thank you):

conda install -c conda-forge numpy

That did the trick for me

0
votes

uninstall existing numpy and install opencv-python will resolve the issue

0
votes

I got this same error in a conda environment, only six+ years later. The other responses were helpful, and eventually I tracked it down to this problem:

> conda list numpy
# packages in environment at [Anaconda3]:
#
# Name                    Version                   Build  Channel
numpy                     1.14.5                   pypi_0    pypi
numpy-base                1.18.1           py36hc3f5095_1
numpydoc                  0.9.1                    pypi_0    pypi

The problem was that 'numpy' was a different version than 'numpy-base'. I solved this with:

> conda install numpy-base=1.14.5

so the two of them matched each other.