1. Is pip the same for 3.4+

   No, it's not. A single pip installation serves a single Python distribution (pip2.7/pip3.4/pip3.5 etc).

2. Since Python 3.5, pip is already bundled with the python distribution, so you can just run python3.6 -m pip instead of pip.

3. Python 3.6 is not available in CentOS 7 vanilla repo. I usually resort to IUS repo when needing to install a fresh Python on CentOS. It always has the most recent Python version, the current one being 3.6.5. It also offers a correspondent pip package.

   $ yum install https://centos7.iuscommunity.org/ius-release.rpm
   $ yum install python36u python36u-devel python36u-pip
   

   Unfortunately, IUS doesn't offer a package for Python 3.7 yet so if you are looking for Python 3.7 on CentOS 7, building from source is your only option.

Edit: when yum is not an option

You should prefer the bootstrapping solution described in this answer as it is the most reliable way to get a working pip installed.

Installing from RPM is generally better, because:

• you can install and uninstall (properly) python3.
• the installation time is way faster. If you work in a cloud environment with multiple VMs, compiling python3 on each VMs is not acceptable.

Solution 1: Red Hat & EPEL repositories

Red Hat has added through the EPEL repository:

• Python 3.4 for CentOS 6
• Python 3.6 for CentOS 7

[EPEL] How to install Python 3.4 on CentOS 6

sudo yum install -y epel-release
sudo yum install -y python34

# Install pip3
sudo yum install -y python34-setuptools  # install easy_install-3.4
sudo easy_install-3.4 pip

You can create your virtualenv using pyvenv:

pyvenv /tmp/foo

[EPEL] How to install Python 3.6 on CentOS 7

With CentOS7, pip3.6 is provided as a package :)

sudo yum install -y epel-release
sudo yum install -y python36 python36-pip

You can create your virtualenv using pyvenv:

python3.6 -m venv /tmp/foo

If you use the pyvenv script, you'll get a WARNING:

$ pyvenv-3.6 /tmp/foo
WARNING: the pyenv script is deprecated in favour of `python3.6 -m venv`

Solution 2: IUS Community repositories

The IUS Community provides some up-to-date packages for RHEL & CentOS. The guys behind are from Rackspace, so I think that they are quite trustworthy...

https://ius.io/

Check the right repo for you here:

https://ius.io/setup

[IUS] How to install Python 3.6 on CentOS 6

sudo yum install -y https://repo.ius.io/ius-release-el6.rpm
sudo yum install -y python36u python36u-pip

You can create your virtualenv using pyvenv:

python3.6 -m venv /tmp/foo

[IUS] How to install Python 3.6 on CentOS 7

sudo yum install -y https://repo.ius.io/ius-release-el7.rpm
sudo yum install -y python36u python36u-pip

You can create your virtualenv using pyvenv:

python3.6 -m venv /tmp/foo

edit: Manual installation and use of setuptools is not the standard process anymore.

If you're running Python 2.7.9+ or Python 3.4+

Congrats, you should already have pip installed. If you do not, read onward.

If you're running a Unix-like System

You can usually install the package for pip through your package manager if your version of Python is older than 2.7.9 or 3.4, or if your system did not include it for whatever reason.

Instructions for some of the more common distros follow.

Installing on Debian (Wheezy and newer) and Ubuntu (Trusty Tahr and newer) for Python 2.x

Run the following command from a terminal:

sudo apt-get install python-pip 

Installing on Debian (Wheezy and newer) and Ubuntu (Trusty Tahr and newer) for Python 3.x

Run the following command from a terminal:

sudo apt-get install python3-pip

On a fresh Debian/Ubuntu install, the package may not be found until you do:

sudo apt-get update

Installing pip on CentOS 7 for Python 2.x

On CentOS 7, you have to install setup tools first, and then use that to install pip, as there is no direct package for it.

sudo yum install python-setuptools
sudo easy_install pip

Installing pip on CentOS 7 for Python 3.x

Assuming you installed Python 3.4 from EPEL, you can install Python 3's setup tools and use it to install pip.

# First command requires you to have enabled EPEL for CentOS7
sudo yum install python34-setuptools
sudo easy_install pip

If your Unix/Linux distro doesn't have it in package repos

Install using the manual way detailed below.

The manual way

If you want to do it the manual way, the now-recommended method is to install using the get-pip.py script from pip's installation instructions.

Install pip

To install pip, securely download get-pip.py

Then run the following (which may require administrator access):

python get-pip.py 

If setuptools is not already installed, get-pip.py will install setuptools for you.

You have to enable the EPEL repo, use:

yum --enablerepo=extras install epel-release

This command will install the correct EPEL repository for the CentOS version you are running.

After this you will be able to install python-pip.

The easiest way I've found to install pip3 (for python3.x packages) on CentOS 7 is:

$ sudo yum install python34-setuptools
$ sudo easy_install-3.4 pip

You'll need to have the EPEL repository enabled before hand, of course.

You should now be able to run commands like the following to install packages for python3.x:

$ pip3 install foo