pip3 install opencv-python fails on 'skbuild'

[Pedroski55]

With some help from askubuntu I got it working:

I used:

sudo apt-get install python3-opencv

I must have installed the module for Python 2!!

I would like to dabble with qr codes.

From here I see I need opencv-python, qrcode and numpy

The FAQ on the link above says:

Q: Pip install fails with ModuleNotFoundError: No module named 'skbuild'?

Since opencv-python version 4.3.0.*, manylinux1 wheels were replaced by manylinux2014 wheels. If your pip is too old, it will try to use the new source distribution introduced in 4.3.0.38 to manually build OpenCV because it does not know how to install manylinux2014 wheels. However, source build will also fail because of too old pip because it does not understand build dependencies in pyproject.toml. To use the new manylinux2014 pre-built wheels (or to build from source), your pip version must be >= 19.3. Please upgrade pip with pip install --upgrade pip.

But, when I try:

pedro@pedro-512ssd:~$ pip3 install --upgrade pip3
Collecting pip3

this fails.

I have:

pedro@pedro-512ssd:~$ pip3 --version
pip 9.0.1 from /usr/lib/python3/dist-packages (python 3.6)

The above FAQ states: "your pip version must be >= 19.3"

I think I should be using pip3, not pip but upgrading pip also fails:

pedro@pedro-512ssd:~$ pip install --upgrade pip
Collecting pip
Cache entry deserialization failed, entry ignored
Could not find a version that satisfies the requirement pip (from versions: )
No matching distribution found for pip
pedro@pedro-512ssd:~$

How can I get cv2 working??

[Clunk_Head]

try: pip3 install opencv-python

[snippsat]

pedro@pedro-512ssd:~$ pip3 install --upgrade pip3
Collecting pip3

this fails.

It is like this no pip3 last when upgrade,test with pip3 -V after.

pip3 install --upgrade pip
# Or if need sudo
sudo pip3 install --upgrade pip

# Then install
pip3 install opencv-python
# Or no sudo
pip3 install --user opencv-python

To get upgrade of all look at pyenv Simple Python Version Management
A 2-minutte demo to install Python 3.8.5 and opencv-python.

# install 3.8.5
mint@mint ~ $ pyenv install 3.8.5
Installing Python-3.8.5...
Installed Python-3.8.5 to /home/mint/.pyenv/versions/3.8.5
 
# Set global(system wide)
mint@mint ~ $ pyenv global 3.8.5

# Test pip
tom@tom-VirtualBox:~$ pip -V
pip 20.2.3 from /home/tom/.pyenv/versions/3.8.5/lib/python3.8/site-packages/pip (python 3.8)

# Install opencv-python
tom@tom-VirtualBox:~$ pip install opencv-python
Collecting opencv-python ...
Successfully installed opencv-python-4.4.0.42

# Test that it work
tom@tom-VirtualBox:~$ python
Python 3.8.5 (default, Sep 15 2020, 12:43:19) 
[GCC 7.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import cv2

>>> 
>>> cv2.__version__
'4.4.0'
>>> exit()