If your project is in python, the only correct file format to use for the config file is python. If your project is in ruby, the config file should be ruby. If

If your project is in python, the only correct file format to use for the config file is python. If your project is in ruby, the config file should be ruby. If you're in $SCRIPTING_LANGUAGE, your config file should be implemented in $SCRIPTING_LANGUAGE. You can use `literal_eval()` (in python, there are similar constructs in basically every scripting language) to prevent prevent people from putting code in the config, but really, it's the person writing the config file's computer, let them do what they want. For compiled languages, it's a bit harder, but there are zero cases where a separate "configuration language" should exist.