How do I use brew installed Python as the default Python?

Question

As you are using Homebrew the following command gives a better picture:

brew doctor

Output:

==> /usr/bin occurs before /usr/local/bin This means that system-provided programs will be used instead of those provided by Homebrew. This is an issue if you eg. brew installed Python.

Consider editing your .bash_profile to put: /usr/local/bin ahead of /usr/bin in your $PATH.

See: How to symlink python in Homebrew?

$ brew link --overwrite python
Linking /usr/local/Cellar/python/2.7.3... 28 symlinks created
$ which python
/usr/local/bin/python

As suggested by the homebrew installer itself, be sure to add this to your .bashrc or .zshrc:

export PATH="/usr/local/opt/python/libexec/bin:$PATH"

Quick fix:

1. Open /etc/paths
2. Change the order of the lines (highest priority on top)

In my case /etc/paths looks like:

/usr/local/bin
/usr/local/sbin
/usr/bin
/bin
/usr/sbin
/sbin

If you want to know more about paths in OSX I found this article quite useful:

http://muttsnutts.github.com/blog/2011/09/12/manage-path-on-mac-os-x-lion/

I did "brew install python" for OSX High Sierra. The $PATH had /usr/local/bin before any other path but still which python was pointing to the system's python.

When I looked deeper I found that there is no python executable at /usr/local/bin. The executable is named python2. To fix this problem create a symbolic link python pointing to python2:

/usr/local/bin $: ln -s python2 python

python formula now uses python3(v3.6.5 for now), brew will link the directory:

/usr/local/opt/python -> ../Cellar/python/3.6.5

it will also link the binary:

/usr/local/bin/python3 -> ../Cellar/python/3.6.5/bin/python3

If you still need to use python2.x, use:

brew install python@2

To use homebrew's python, just put its directory in PATH, for bash:

export PATH="/usr/local/opt/python/libexec/bin:$PATH"

for fish:

set -x PATH /usr/local/opt/python/libexec/bin $PATH

Note:

1. doing this will shadow the system default version of python
2. homebrew used to link python to /usr/local/share/python in older versions.

Homebrew does NOT replace stuff in "/usr/bin". You'll just want to put "/usr/local/bin" ahead of "/usr/bin" in your path, then "which python" will give you "/usr/local/bin/python".

Replacing /usr/bin/python (or /usr/bin/ruby) is highly unrecommended.