I took the 9th practical exam over the weekend. At first, I was confused by the difficulty of Type 1, but I solved it by dividing the rows one by one with iloc.. While solving this Type 1, I felt that I didn't know How to use the in-depth loop (I knew the principle because of the label encoding, but I didn't have time to think because I couldn't access various types.), How to fill in the missing values with the average values obtained by group by with the same conditions (there were too many cases, so it was impossible to fill in the missing values one by one.) The process was complicated, but since the exam time was 3 hours, I think I could solve these problems even if I just worked hard and listened to the lectures.