Example of Python aliases + reimplementation of `cd` to auto de/activate the current virtualenv

.zshrc

# aliases
alias -g ll='ls -al'
alias -g subl='open -a "Sublime Text"'
alias server='python3 -m http.server 8000 --bind 127.0.0.1'
alias rmvenv='deactivate && rm -rf venv/'
alias venv='python3 -m venv venv'
alias activate='source venv/bin/activate'
alias pipupgrade='python3 -m pip install --upgrade pip'
alias requirements='python3 -m pip install -r requirements.txt'

# python virtualenv auto de/activation
function cd() {
  if [[ -d ./venv ]] ; then
    deactivate
  fi

  builtin cd $1

  if [[ -d ./venv ]] ; then
    . ./venv/bin/activate
  fi

  # also add node_modules/.bin to $PATH
  if [[ -d ./node_modules ]] ; then
    export PATH="$(npm bin):$PATH"
  fi
}