set python3 as default mac

C++
$ brew update && brew upgrade python $ pyenv global 3.7.3
# and verify it worked 
$ pyenv version
3.7.3 (set by /Users/mbbroberg/.pyenv/version)$ brew install pyenv # Go into your .zshrc file. Is there a line that reads:
alias python='python3'# it is said not to do but I used it anyway, because of the conveniency
$ echo "alias python=/usr/local/bin/python3.7" >> ~/.zshrc 
Source

Also in C++: