I have the same error. It seems Boston dataset is removed from scikit-learn. Since mglearn lib also calls load_boston, the import of mglearn results in error.

I am using Google Colab and used the following:

pip install "scikit-learn<1.2"

When I try to import mglearn, it worked.

Yeah, seems a chronic error, because I can't find a post about it. That makes it impossible to call any method or function about.

So sad. I really want to practice by using it

Yes, downgrading is currently the only solution, sorry. The book needs to be rewritten with a different dataset.

I'll try to do a temporary fix asap.