Make Python From Source

I ran into a situation where I needed to use Python3 rather then Python 2.7 so I cooked up a Makefile so I could do it whenever I needed to again. This way I can keep my older Python installs and not break some Linux packages as I can refer to my new alias python3 at the command-line while still being able to call python at any time for older versions.

It should work on any YUM or APT-GET based Linux OS, Tested it on Centos6 and Ubuntu14.

Changing the value of PYTHON_BRANCH lets you pull down any specific branch from the cPython GitHub (latest as of writing this is 3.5), changing the value of CORES to be -j4, or -j8 lets you use more cores when compiling from source (4 cores, and 8 cores respectively.)

Enjoy.

#NEED PYTHON 3
PYTHON_BRANCH=3.4
CORES=-j2
YUM=$(shell which yum)
APT=$(shell which apt-get)
TOOLS=git gcc
INSTALL_ROOT:=$(shell echo $$PWD/dist/)

git:
ifneq ($(YUM),)
    which $(TOOLS) || yum -y install git \
    gcc gcc-c++ \
    zlib-devel openssl-devel
endif
ifneq ($(APT),)
    which $(TOOLS) || apt-get install -y git gcc g++ man zlib1g-dev libssl-dev
endif

python-src:
    git clone --branch $(PYTHON_BRANCH) https://github.com/python/cpython.git python3

python-build:
    (cd python3/; \
    ./configure; \
    make -s $(CORES); \
    make -s $(CORES) altinstall)

install: git python-src python-build