doapi.sh

{
  echo '{'
  for endpoint in sizes regions images ssh_keys; do
    echo -n '"'$endpoint'": '
    curl -s "https://api.digitalocean.com/${endpoint}/?client_id=${DO_CLIENT_ID}&api_key=${DO_API_KEY}"
    echo ','
  done | sed '$s/,$//'
  echo '}'
} | python -mjson.tool

Like the original but does not require bash array and output a parsable JSON.