如何根据 python 中的另一个列值从列中找到最常见的值？

Question

I have a dataframe (DF) that has the following columns: UserID, Country, Arrival_Year, Airport_Code. Each country is listed several times based on UserID.

I want to know the most common arrival year for each country listed in the data frame. How can I calculate that?

Tried using value counts but not getting the right answer.

Answer 1

Try using pandas groupby with mode:

df.groupby('Country')['ArrivalYear'].apply(lambda x: x.mode()[0])