Build and Install Python3 from the Source
You can always build python3 from its source manually. Since you can choose the version of python3 to install, this is the surest way to meet Python dependency requirement.

Here is how you can build and install python3 from the source.

First, install minimum necessary tools:
Code:
$ sudo yum install yum-utils
Then using yum-builddep, set up a necessary build environment for python3 and install missing dependencies. The following command will automatically take care of that.
Code:
$ sudo yum-builddep python
Now download the latest python3 (e.g., python 3.5) from https://www.python.org/ftp/python/
Code:
$ curl -O https://www.python.org/ftp/python/3.5.0/Python-3.5.0.tgz
Finally, build and install python3 as follows. The default installation directory is /usr/local. If you want to change this to some other directory, pass "--prefix=/alternative/path" parameter to configure before running make.
Code:
$ tar xf Python-3.5.0.tgz
$ cd Python-3.5.0
$ ./configure
$ make
$ sudo make install
This will install python3, pip3, setuptools as well as python3 libraries on your CentOS system.