macOS 10.12
Seems like the same problem here but top answers just led to more questions.
Top answer says to do:
brew link --overwrite python
which yields:
Warning: Already linked: /usr/local/Cellar/python/3.6.5
To relink: brew unlink python && brew link python
I'm pretty sure I need to get homebrew to switch to 2.7 rather than using version 3. I do
brew unlink python && brew link python
and get:
Unlinking /usr/local/Cellar/python/3.6.5... 25 symlinks removed
Linking /usr/local/Cellar/python/3.6.5... 25 symlinks created
Is there a way I can tell it to link to a specific version? /usr/local/Cellar/python/ contains: 2.7.13   2.7.14   2.7.14_3 3.6.3    3.6.5
How can I get my system to always use 2.7.14_3?
/usr/local/opt/python/bin contains python3, python3-config, and 3.6 versions. How can I get 2.7 in here and remove 3 and 3.6?
Also which python returns /usr/bin/python. When I type python -V I get Python 2.7.10. /usr/bin contains python2.7, python2.7-config as well as some other seemingly-python-related things (but no python3, which is good I think). Is this different from homebrew pythons? Thanks in advance. 
Edit:
Second-to-top answer says to do head -n1 /usr/local/bin/pip which returns 
head: /usr/local/bin/pip: No such file or directory
and
mv /usr/local/bin/pip /usr/local/bin/pip.old 
returns
mv: rename /usr/local/bin/pip to /usr/local/bin/pip.old: No such file or directory
 
    