iris dataset

[psteinb]

Taken from the mentor feedback:

For the Iris dataset, for some learners it was not clear how to access the columns "sepal width (cm)"; they tried with . attribute access, similar to the lecture videos, but obviously this won't work if the column name contains spaces. So either this should be clarified in the exercise description or the lecture should also use __getitem__ access (df["sepal width (cm)"]); the latter is more consistent in my opinion.