使用 Pandas，对于以下数据集
author1,category1,10.00
author1,category2,15.00
author1,category3,12.00
author2,category1,5.00
author2,category2,6.00
author2,category3,4.00
author2,category4,9.00
author3,category1,7.00
author3,category2,4.00
author3,category3,7.00
我想得到每个作者的最高值
author1,category2,15.00
author2,category4,9.00
author3,category1,7.00
author3,category3,7.00
(抱歉，我是 Pandas 菜鸟。)
请您参考如下方法:
import pandas as pd
df = pd.read_csv("in.csv", names=("Author","Cat","Val"))
print(df.groupby(['Author'])['Val'].max())
获取df:
inds = df.groupby(['Author'])['Val'].transform(max) == df['Val']
df = df[inds]
df.reset_index(drop=True, inplace=True)
print(df)
Author Cat Val
0 author1 category2 15
1 author2 category4 9
2 author3 category1 7
3 author3 category3 7
