Building and installing python3.x with python2.x in Linux

RHEL 6.x doesn't comes with python3. So if any of your project require python3 and also some of the projects need python2 then you may need those 2 version same time in your system.

Prerequisite:
gcc (C89)/g++
ld
ranlib


How:
1. Download python3.x package from https://www.python.org/downloads/release/python-343/
2. Extract it and move inside the package python-3.4.3

$ cd /python-3.4.3

3. Open a console and run the following configure command. We will build python with shared library support as many of the other project will require python3 dynamic library linking.

so, configure it by,

$ ./configure --prefix=/opt/python3 --enable-shared

We are putting build output directory as /opt/python3.

4. After completion now build it by,

$ make

 5. Then install it by alternate installation by,

$ make altinstall

6. Now create a symlink of the newly created python3 binary and copy the shared library to the /lib64/ directory of filesystem.

$ ln -s /opt/python3/bin/python3.4 /usr/bin/python3

$ cp /opt/python3/libpython3.* /lib64/

7.  Now run python script by,

 $ python3 my.py

And your python2 is also ok and usable!