[FIXED] Failed to upgrade pip3 on Mac with Homebrew Python

Issue

I failed at upgrading pip3 on mac and get confusing (for me) answers in the terminal:

> which python
/usr/bin/python

> pip -V
pip 9.0.1 from /Library/Python/2.7/site-packages/pip-9.0.1-py2.7.egg (python 2.7)

> which python3
/usr/local/bin/python3

> python3 -V
Python 3.6.4

> pip3 -V
pip 7.1.0 from /usr/local/lib/python3.6/site-packages (python 3.6)

> sudo -H pip3 install --upgrade pip
You are using pip version 7.1.0, however version 9.0.1 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
Requirement already up-to-date: pip in /usr/local/lib/python3.6/site-packages

> sudo -H pip3 install --upgrade pip3
Could not find a version that satisfies the requirement pip3 (from versions: )
No matching distribution found for pip3

Why can't I have pip3 upgraded to 9.0?

---

Solution was to force reinstall:

sudo -H pip3 install --upgrade pip --force-reinstall

Solution

Verify that /usr/local/bin/pip3 --version is 9.0.1. If not:

sudo python3 -m pip install --upgrade pip

I.e., use pip package from that particular Python version.

Answered By - phd