Get brew install pyenv pyenv-virtualenv
Then install python3.
See all available versions pyenv install -l
Install stable version 3 like pyenv install 3.9.7
Then create a virtual env giving it a name (py3 here)
pyenv virtualenv 3.9.7 py3
Add to .zshrc
eval "$(pyenv init -)"
export PATH="$(pyenv root)/shims:$PATH"
export PATH="$(pyenv root)/bin:$PATH"
Add to .zprofile
eval "$(pyenv init --path)"
Above steps are all one-time.
Now create a new terminal. In the folder where you want to use py3:
pyenv local py3
Now everytime you enter that folder it will automatically switch to py3
Verify by:
$python -V
$pyenv which python
Run pip install -r requirements.txt to install all required libraries.