Determines the Astropy cache directory name and creates the directory if it doesn’t exist.

This directory is typically $HOME/.astropy/cache, but if the XDG_CACHE_HOME environment variable is set and the $XDG_CACHE_HOME/astropy directory exists, it will be that directory. If neither exists, the former will be created and symlinked to the latter.

cachedir : str

The absolute path to the cache directory.