If you need a portable Python 3.7.3 for development, download from Github indygreg repo, untar and move to /opt/python/3.7.3
folder (create if not exists)
sudo apt install -y libreadline-dev libbz2-dev libncursesw5-dev libgdbm-dev zlib1g-dev liblzma-dev libsqlite3-dev libssl-dev libffi-dev
cd /opt
sudo wget https://www.python.org/ftp/python/3.7.3/Python-3.7.3.tgz
sudo tar -xvf Python-3.7.3.tgz
sudo rm Python-3.7.3.tgz
sudo chown -R $USER:$USER /opt/Python-3.7.3
cd /opt/Python-3.7.3
./configure --prefix=/opt/Python3.7
make -j4
sudo make install