error installing rpy2 on Mac

Question

I am trying to install rpy2 on python 2.7.14, on a Mac OS High Sierra version 10.13.2, but when I try writing the command

pip install rpy2

I get the following output:

Collecting rpy2
  Using cached rpy2-2.9.2.tar.gz
    Complete output from command python setup.py egg_info:
    rpy2 is no longer supporting Python < 3. Consider using an older rpy2 release when using an older Python release.

    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /private/var/folders/11/xgl2d8l16wd8xv2_lmdtcmwc0000gn/T/pip-build-aJMHfU/rpy2/
You are using pip version 9.0.1, however version 9.0.3 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.

I have already tried to upgrade the pip package by typing

pip install --upgrade pip

but I get the following message:

Requirement already up-to-date: pip in /usr/local/lib/python2.7/site-packages
You are using pip version 9.0.1, however version 9.0.3 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.

I was able to install rpy2 on python3, but for some reason it is not installing on python2.

Here are the specifications from my python2:

Python 2.7.14 (v2.7.14:84471935ed, Sep 16 2017, 12:01:12) 
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.

Any help would be deeply appreciated!

Answer 1

Version 2.8.6 was the last version of rpy2 which supported the 2.x series of Python.

You can tell pip to install that version specifically:

pip install rpy2==2.8.6

_{Why a package manager - whose entire purpose in life is to handle dependency management - is not able to successfully figure this out on its own, I have no clue.}