Installs python3 on CentOS

install-python3-centos7.sh

# !/bin/bash

# Problem:
# CentOS ships with Python as a critical part of the base system. 
# Because it is a critical part it is not getting updated, other than to plug security vulnerabilities. 
# CentOS 7 users are stuck with Python 2.7.5 released in May 2013.

# Utilities such as yum will break if the default Python interpreter is upgraded or replaced. 
# The trick is to install new versions of Python in /usr/local (or some other non-standard location) so that 
#   they can live side-by-side with the system version.

# source: https://danieleriksson.net/2017/02/08/how-to-install-latest-python-on-centos/

# make sure the system is up-to-date:
yum update

# Compilers and related tools:
yum groupinstall -y "development tools"

# Libraries needed during compilation to enable all features of Python:
yum install -y zlib-devel bzip2-devel openssl-devel ncurses-devel sqlite-devel readline-devel tk-devel gdbm-devel db4-devel libpcap-devel xz-devel expat-devel libffi-devel

# If you are on a clean "minimal" install of CentOS you also need the wget tool:
yum install -y wget

# Python 3.7.2 (this will take a while...):
wget http://python.org/ftp/python/3.7.2/Python-3.7.2.tar.xz
tar xf Python-3.7.2.tar.xz
cd Python-3.7.2
./configure --prefix=/usr/local --enable-optimizations --enable-shared LDFLAGS="-Wl,-rpath /usr/local/lib"
make && make altinstall

# Test if it works
Python3.7 -V
pip3.7 -V

# remember, to install via pip use: 
# pip3.7 install <package>
# (! and not: pip install <package>)