OS :debian8.
debian8@hwy:~$ sudo apt-get install python3
Reading package lists... Done
Building dependency tree
Reading state information... Done
python3
wget https://www.python.org/ftp/python/3.6.0/Python-3.6.0.tar.xz
tar -xf Python-3.6.0.tar.xz
cd ./Python-3.6.0
sudo ./configure --prefix=/usr/local/python3.6 --with-ensurepip=install
sudo make
sudo make install
sudo ln -s /usr/local/python3.6/bin/python3.6 /usr/bin/python3.6
sudo ln -s /usr/local/python3.6/bin/pip3.6 /usr/bin/pip3.6
All issues solved.
~$ dpkg -l python3
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Architecture Description
+++-===================-==============-==============-============================================
ii python3 3.5.1-3 amd64 interactive high-level object-oriented langu
~$ which python3
/usr/bin/python3
apt install --reinstall python3