Python Grouping (groupby)

df.groupby("Pclass") creates groups grouped by Pclass.

Here, you usually name the column and apply the collective function to it.

df.groupby("Pclass")["Age"].max() This will result in the largest age in each group.

Since the questioner's code did not specify the column name to perform max or min, it will perform max and min for all columns. However, depending on the type of column, max, min cannot be obtained because there are also columns (you can't tell the size of a regular string), so I think an error occurred for those columns.