Hi again,
I've issued a pull request to the yt_astro_analysis module that should fix this issue. Please have a look at that at the link below if you like.
Note that you'll need to install yt_astro_analysis (from source) and update the imports in your script accordingly. You can find information on how to do both of those here:
Let us know if you have any questions or something still doesn't work right.
Britton