OpenCV for raspberyy pi 3b+ install

//make sure os is current
sudo apt-get update
sudo apt-get -y dist-upgrade
sudo apt-get update
sudo apt-get upgrade
//configure SSH utilities
sudo apt-get install screen
sudo apt-get install htop
//free up >1GB of data, deleting Wolfram and Libreoffice (Wont need these)
sudo apt-get purge wolfram-engine
sudo apt-get purge libreoffice*
sudo apt-get clean
sudo apt-get autoremove
//install dependencies
sudo apt-get install build-essential cmake pkg-config
sudo apt-get install libjpeg-dev libtiff5-dev libjasper-dev libpng12-dev
sudo apt-get install libavcodec-dev libavformat-dev libswscale-dev libv4l-dev
sudo apt-get install libxvidcore-dev libx264-dev
sudo apt-get install libgtk2.0-dev libgtk-3-dev
sudo apt-get install libatlas-base-dev gfortran
//install Python 3
sudo apt-get install python3-dev
//install pip3 (package installer)
sudo apt-get install python3-pip
//get OpenCV source code (version 3.4.3)
wget -O opencv.zip https://github.com/opencv/opencv/archive/3.4.3.zip
wget -O opencv_contrib.zip https://github.com/opencv/opencv_contrib/archive/3.4.3.zip
unzip opencv.zip
unzip opencv_contrib.zip
//install Numpy,Scimp (for python)
sudo pip3 install numpy scipy
//compile OpenCV
cd ~/opencv-3.4.3/
mkdir build
cd build
cmake -D CMAKE_BUILD_TYPE=RELEASE \
    -D CMAKE_INSTALL_PREFIX=/usr/local \
    -D INSTALL_PYTHON_EXAMPLES=ON \
    -D OPENCV_EXTRA_MODULES_PATH=~/opencv_contrib-3.4.3/modules \
    -D BUILD_EXAMPLES=ON ..
//build OpenCV
make -j4
sudo make install
sudo ldconfig
sudo apt-get update
sudo reboot