CentOS 6.8 (64 bits)

# If this library is not installed ahead, the following exception will be raised. 
# ModuleNotFoundError: No module named '_ctypes'
> yum install libffi-devel
 
#If this library is not installed ahead, the following error will appear. 
# zipimport.ZipImportError: can't decompress data; zlib not available
> yum install zlib-devel

> wget https://www.python.org/ftp/python/3.7.4/Python-3.7.4.tgz
> tar -zxvf Python-3.7.4.tgz
> rm -f Python-3.7.4.tgz
 
# create the install directory
> mkdir /usr/local/python3.7.4
 
> cd Python-3.7.4
> ./configure --prefix=/usr/local/python3.6.3 --enable-optimizations
> make
> make altinstall
 
# redirect link
> mv /usr/bin/python /usr/bin/python.bak
> ln -s /usr/local/python3.7.4/bin/python3.7 /usr/bin/python
 
# To check the version
> python --version