TypeError: 'SubstructLibrary' object is not iterable in "UPGMA_classification-rdkit.ipynb"

[chengthefang]

Hi all,

I was following the instruction and tried to run the "UPGMA_classification-rdkit.ipynb". But I ran into a Type Error as shown below:

Here is my package version:
RDKit version: 2021.09.2
Pandas version: 1.3.4
Numpy version: 1.20.3
MatplotLib version: 3.5.0
Sklearn version: 1.0.1
Seaborn version: 0.11.2

Does anyone have the same issue? Or would you mind helping me figure out the issue?

Thanks!
Cheng