can not run vdeo_emotion_color_demo.py about face_classification

[mirceaciu]

I had an similar issue on my embedded Ubuntu board.

I was using OpenCv installed with apt-get or pip. My problem was solved after compiling OpenCv

How did you install OpenCv, and what Os do you use?

[gubiniliya]

Ubuntu 17.10 x64 desktop
pip install opencv2-python
or
pip3 install opencv-python
I do not remember exactly, but likely pip3 install opencv-python
$ sudo apt-get install opencv
not found this packege

may be i need reinstall opencv?

[oarriaga]

You need to compile openCV since the pip installation does not include the VideoCapture functionalities. I would recommend following this guide. Which is the same guide I believe @mirceaciu gave you.

[gubiniliya]

Completely following the instructions, I ran into the problem in step where using cmake
The previous steps were fully implemented and passed successfully, but when entering the command

cmake -D CMAKE_BUILD_TYPE=RELEASE \
    -D CMAKE_INSTALL_PREFIX=/usr/local \
    -D INSTALL_PYTHON_EXAMPLES=ON \
    -D INSTALL_C_EXAMPLES=OFF \
    -D OPENCV_EXTRA_MODULES_PATH=~/opencv_contrib-3.1.0/modules \
    -D PYTHON_EXECUTABLE=~/.virtualenvs/cv/bin/python \
    -D BUILD_EXAMPLES=ON ..

in build dir with using workon cv where cmake end i have

Configuring incomplete, errors occurred!
See also "/home/gubiniliya/opencv/opencv-3.3.0/build/CMakeFiles/CMakeOutput.log".
See also "/home/gubiniliya/opencv/opencv-3.3.0/build/CMakeFiles/CMakeError.log".

I tried restarting with deleting the build folder, but it did not help. I also tried to do this after rebooting - the same result
strange and the fact that the section Python is also not similar to the one in the instruction
I do everything for Python 3

-- 
--   Python 2:
--     Interpreter:                 NO
-- 
--   Python 3:
--     Interpreter:                 /home/gubiniliya/.virtualenvs/cv/bin/python3 (ver 3.6.3)
-- 
--   Python (for build):            /home/gubiniliya/.virtualenvs/cv/bin/python3
-- 

I'll attach logs, maybe you'll advise something or tell me that you need some option to add or remove
CMakeError.log
CMakeOutput.log
Naturally to step make -j I can not go, because the project is not building