2

I wanted to ask a specific question before I try anything else and possibly ruin my Anaconda distribution.

conda version: 4.7.11
anaconda version: 2019.07
python version: 3.7.3

I installed opencv-python per the instructions here:

(base) C:\Users\...>pip install opencv-python

I thought this had worked because I was able to run defs from import cv2 in my Spyder IDE, and conda list returned:

...
numpydoc                  0.9.1                      py_0
olefile                   0.46                     py37_0
opencv-python             4.1.1.26                 pypi_0    pypi
openpyxl                  2.6.2                      py_0
...

However, I quickly ran into problems when attempting the tutorial. Specifically, img = cv2.imread('messi5.jpg',0) would return a None object. I tried img = cv2.imread(r'C:\path_to_my_image.jpg',0) with a local photo, and it correctly returned a 2D, grayscale object array. I'm confident I simply failed to install the photo library that comes with opencv.

I anticipated more problems and did some digging, where I found this answer shows that I probably did not install the correct version of cv. I attempted to uninstall using pip, but had a text file from the active directory open, and got a permission error!

(base) C:\Users\triton>pip uninstall opencv-python
Uninstalling opencv-python-4.1.1.26:
  Would remove:
    c:\users\triton\anaconda3\lib\site-packages\cv2\*
    c:\users\triton\anaconda3\lib\site-packages\opencv_python-4.1.1.26.dist-info\*
Proceed (y/n)? y
ERROR: Exception:
Traceback (most recent call last):
  File "C:\Users\triton\Anaconda3\lib\shutil.py", line 563, in move
    os.rename(src, real_dst)
PermissionError: [WinError 32] The process cannot access the file because it is being used by another process: 'c:\\users\\triton\\anaconda3\\lib\\site-packages\\opencv_python-4.1.1.26.dist-info\\' -> 'c:\\users\\triton\\anaconda3\\lib\\site-packages\\~pencv_python-4.1.1.26.dist-info'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\triton\Anaconda3\lib\site-packages\pip\_internal\cli\base_command.py", line 178, in main
    status = self.run(options, args)
  File "C:\Users\triton\Anaconda3\lib\site-packages\pip\_internal\commands\uninstall.py", line 75, in run
    auto_confirm=options.yes, verbose=self.verbosity > 0,
  File "C:\Users\triton\Anaconda3\lib\site-packages\pip\_internal\req\req_install.py", line 823, in uninstall
    uninstalled_pathset.remove(auto_confirm, verbose)
  File "C:\Users\triton\Anaconda3\lib\site-packages\pip\_internal\req\req_uninstall.py", line 388, in remove
    moved.stash(path)
  File "C:\Users\triton\Anaconda3\lib\site-packages\pip\_internal\req\req_uninstall.py", line 277, in stash
    renames(path, new_path)
  File "C:\Users\triton\Anaconda3\lib\site-packages\pip\_internal\utils\misc.py", line 305, in renames
    shutil.move(old, new)
  File "C:\Users\triton\Anaconda3\lib\shutil.py", line 575, in move
    rmtree(src)
  File "C:\Users\triton\Anaconda3\lib\shutil.py", line 513, in rmtree
    return _rmtree_unsafe(path, onerror)
  File "C:\Users\triton\Anaconda3\lib\shutil.py", line 401, in _rmtree_unsafe
    onerror(os.rmdir, path, sys.exc_info())
  File "C:\Users\triton\Anaconda3\lib\shutil.py", line 399, in _rmtree_unsafe
    os.rmdir(path)
PermissionError: [WinError 32] The process cannot access the file because it is being used by another process: 'c:\\users\\triton\\anaconda3\\lib\\site-packages\\opencv_python-4.1.1.26.dist-info\\'

I closed the text file and tried to run pip uninstall opencv-python again, but now receive:

(base) C:\Users\triton>pip uninstall opencv-python
WARNING: Skipping opencv-python as it is not installed.

I do not know if this warning is accurate, because conda list still shows opencv-python as an available package:

...
olefile                   0.46                     py37_0
opencv-python             4.1.1.26                 pypi_0    pypi
openpyxl                  2.6.2                      py_0
openssl                   1.1.1c               he774522_1
...

i finally tried conda remove opencv-python but it says the packages aren't found?!

(base) C:\Users\triton>conda remove opencv-python
Collecting package metadata (repodata.json): done
Solving environment: failed

PackagesNotFoundError: The following packages are missing from the target environment:
  - opencv-python

I want to perform a clean opencv3 install via this method, but don't know if there will be some library conflicts or something. I am severely confused about what's happening here, and wanted to get advice before trying to alter my distribution any further. It's not the end of the world if I need to reinstall Anaconda entirely, but I thought i would share these problems in case someone else runs into them!

How can I be sure all opencv pip files are completely removed, without doing a clean reinstall of Anaconda?

Thanks in advance for your help!

T Walker
  • 330
  • 1
  • 3
  • 12
  • Create a virtual environment and install either with conda or pip as you like. If it doesn’t work out, you could just delete that environment. – CypherX Sep 16 '19 at 00:55
  • Go to environments, and simply search for the module you wish to disable, when it appears, untick the desired module and click 'apply' to disable. – Dylan Freeman Sep 16 '19 at 09:29
  • "CypherX" comment does not solve the question, in which i do not want left over files in my base environment. i did not try "Dylan Freeman" 's suggestion, but have already done a clean install of anaconda. However, working with environments are good suggestions, and i'll probably use an older version of python with opencv in an env separate from my base env. – T Walker Sep 16 '19 at 14:35

2 Answers2

1

Cause the package was installed by pip, you have to uninstall the package by pip uninstall.

The problem is that the uninstallation was interrupted cause some files are being taken by another process.

To solve this, reinstall the package. Then uninstall it.

pip install opencv-python -f
pip uninstall opencv-python
Simba
  • 23,537
  • 7
  • 64
  • 76
  • i ended up doing a clean install of anaconda to simplify things. although, i did not try you're suggestion, i'm pretty sure this would've worked. someone else will have to test this if they ever come across the same problem. thanks to everybody for the comments! – T Walker Sep 16 '19 at 14:31
0

Note: that in an anaconda environment pip=pip3 unless you have both python 2&3 installed.

So if you only have one installed in the environment, then:

conda activate MyEnv
pip uninstall opencv-python
Amar Khan
  • 11
  • 1