# cd /usr/local/src/

# ls

Python-3.5..tgz

# tar -xf Python-3.5..tgz

# ls

Python-3.5.  Python-3.5..tgz

# cd Python-3.5./

# yum install gcc

# gcc -v

gcc version 4.8.  (Red Hat 4.8.-) (GCC)

# ./configure

# yum install openssl-devel -y

# make && make install

# rm -rf /usr/bin/python

]# ln -s /usr/local/bin/python3. /usr/bin/python

# python -V

Python 3.5.