python - 删除重复项，但保留每组给定列中具有最大值的行

Question

我有一个这样的DF：

    Name        Gender         Age      Level
  Pikachu        Male           4         8
 Charmander     Female          5         7
 Charmander     Female          5         7
 Squirtle        Male           3         6
 Squirtle        Male           3         9
 Squirtle       Female          4         9

我希望它看起来像这样：

   Name        Gender         Age      Level
  Pikachu        Male           4         8
 Charmander     Female          5         7
 Squirtle        Male           3         9
 Squirtle       Female          4         9

我不知道如何用英语解释我想做什么，所以我会用伪代码来写。

基本上：

If Name, Gender and Age are the same:
      If there is a difference in levels:
            Keep the row with higher level
      If there is a tie:
            Keep a random one

任何想法表示赞赏！

标签： pythonpandasdataframegroup-by

Answer 1

用sort_values+检查drop_duplicates

df=df.sort_values('Level').drop_duplicates(['Name','Gender','Age'],keep='last')
df
         Name  Gender  Age  Level
2  Charmander  Female    5      7
0     Pikachu    Male    4      8
4    Squirtle    Male    3      9
5    Squirtle  Female    4      9