analyse unused class and functions (using ag)

unused.sh

#!/bin/sh

set -e

target_directory=${1-.}

export IFS='
'
for target in $(ag -o '((class|def)\s+(\w+))'); do
  target_name=$(echo $target | ag -o '\w+$')
  occurance=$(ag -Q $target_name $target_directory --py | wc -l)
  if [ $occurance -eq 1 ]; then
    echo $target
  fi
done