Python has been installed as
  /usr/local/bin/python3

Unversioned symlinks `python`, `python-config`, `pip` etc. pointing to
`python3`, `python3-config`, `pip3` etc., respectively, have been installed into
  /usr/local/opt/python/libexec/bin

pip 19.1.1 from /usr/local/lib/python3.7/site-packages/pip (python 3.7)

$ ls -l /usr/local/lib/python3.7/site-packages/
drwxr-xr-x  19 root    admin    608 Jun 29 00:07 youtube_dl
drwxr-xr-x  10 root    admin    320 Jun 29 00:07 youtube_dl-2019.6.27.dist-info

PATH="/usr/local/Cellar/python/3.7.4/Frameworks/Python.framework/Versions/3.7/bin:${PATH}:${HOME}/go/bin"
export PATH