Direnv script to manage Python virtual environments

.envrc

export PYTHONPATH=$(pwd)

RED='\033[0;31m'
GREEN='\033[0;32m'
PURPLE='\033[0;35m'
YELLOW='\033[1;33m'
NC='\033[0m'

error () { printf "${RED}[!]${NC} ${1}\n"; }
info () { printf "${GREEN}[~]${NC} ${1}\n"; }
warning () { printf "${YELLOW}[?]${NC} ${1}\n"; }
fmt-file () { echo "${PURPLE}${1}${NC}"; }

if [ ! -f ".venv/bin/activate" ]; then
    error "Creating virtual environment in $(fmt-file .venv/)"
    virtualenv .venv
fi

info "Activating virtual environment from $(fmt-file .venv/)"
source .venv/bin/activate
unset PS1

if [ ! -f "requirements.txt" ]; then
    warning "no $(fmt-file requirements.txt), skipping Python version check"
    exit 0
fi

e=$(grep '^# python==' requirements.txt | sed 's/# python==//')
if [ -z "$e" ]; then
    warning "no Python version in $(fmt-file requirements.txt), skipping Python version check"
    exit 0
fi

v=$(python --version | sed 's/^Python //')
if [ "$e" = "$v" ]; then
    info "Version is ${v}"
else
    warning "Version should be ${e}, found ${v}"
fi