Switch between two version of gcc

Question

By default my system uses gcc 5.4.0 in ubuntu 16.04 to run a specific program l need to switch to gcc 4.8.

My question is the following :

How can l switch to gcc 4.8 before running the program and come back to gcc 4.8.4 once l've finished. The program l have to run is in python :

# what to do befor running the program
# python3.6 main.py
# how to come back to the gcc version by default 

Here are the differents gcc version l have :

dpkg -l | grep gcc | awk '{print $2}'
gcc
gcc-4.8
gcc-4.8-base:amd64
gcc-4.9
gcc-4.9-base:amd64
gcc-5
gcc-5-base:amd64
gcc-6-base:amd64
gir1.2-packagekitglib-1.0
lib32gcc1
libcaca0:amd64
libgcc-4.8-dev:amd64
libgcc-4.9-dev:amd64
libgcc-5-dev:amd64
libgcc1:amd64
libpackagekit-glib2-16:amd64
libunity-action-qt1:amd64
libwebrtc-audio-processing-0:amd64
qtchooser
qtdeclarative5-unity-action-plugin:amd64

EDIT1 Is it correct if l do the following as suggested in https://askubuntu.com/questions/26498/choose-gcc-and-g-version

Have l set that correclty ?

sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.8 10
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.9 20
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-5 30

sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-4.8 10
sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-4.9 20
sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-5 30

sudo update-alternatives --install /usr/bin/cc cc /usr/bin/gcc 40
sudo update-alternatives --set cc /usr/bin/gcc

sudo update-alternatives --install /usr/bin/c++ c++ /usr/bin/g++ 40
sudo update-alternatives --set c++ /usr/bin/g++

But l stack at the last command :

sudo update-alternatives --config gcc
sudo update-alternatives --config g++

do l need to set that as :

sudo update-alternatives --config gcc-4.8
sudo update-alternatives --config g++-4.8

and when l want to come back to gcc 5 l set it to :

sudo update-alternatives --config gcc-5
sudo update-alternatives --config g++-5

Am l right ?

EDIT2 l need to run python3.6 with gcc 4.8.4 . The default gcc version of python3.6 is 4.4.7

root@ahmed-OMEN-by-HP-Laptop:~# python3.6
Python 3.6.0 |Anaconda custom (64-bit)| (default, Dec 23 2016, 12:22:00) 
[GCC 4.4.7 20120313 (Red Hat 4.4.7-1)] on linux
Type "help", "copyright", "credits" or "license" for more information.

How can l change that ?