An actual working opencv installer maybe

opencv_install.sh

#!/user/bin/env bash

sudo apt-get update -y
sudo apt-get upgrade -y

sudo apt-get install -y build-essential cmake pkg-config
sudo apt-get install -y libjpeg8-dev libtiff5-dev libjasper-dev libpng12-dev
sudo apt-get install -y libavcodec-dev libavformat-dev libswscale-dev libv4l-dev
sudo apt-get install -y libxvidcore-dev libx264-dev
sudo apt-get install -y libgtk-3-dev
sudo apt-get install -y libatlas-base-dev gfortran
sudo apt-get install -y python3
sudo apt-get install -y python3-dev
sudo apt-get install -y python
sudo apt-get install -y python-dev
sudo pip3 install numpy

read -p "Press enter to continue"

cd
wget -O opencv.zip https://github.com/opencv/opencv/archive/3.3.0.zip
unzip opencv.zip
wget -O opencv_contrib.zip https://github.com/opencv/opencv_contrib/archive/3.3.0.zip
unzip opencv_contrib.zip

rm opencv.zip
rm opencv_contrib.zip

cd opencv-3.3.0/
mkdir build
cd build
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-3.3.0/modules     -D PYTHON_EXECUTABLE=/usr/bin/python3     -D BUILD_EXAMPLES=ON .. 
make -j4
sudo make install
sudo ldconfig
python3