I found this lesson pretty confusing. I would have appreciated it if they first explained the syntax of the code after the split method. :
split_df = df['exerciseDescription'].str.split('(\d+)', expand=True)
It was also unclear what expand does. I get that they expect you to read other material or resources, but I would have appreciated it if they had at least referred us to that part of the documentation to get a better understanding of the syntax.