pandas 更复杂 sql 查询的语法

Question

我正在寻找 pandas 语法来对 Pandas DataFrame 进行聚合。我找不到如何在 pandas.

中完成以下 sql 查询的示例

#sum and divide
select
 click,
 ctr,
 SUM(click)/SUM(imp) as ctr
from mytable
group by website

#normalize each subgroup 
select
 imp,
 imp/SUM(imp) Over (partition website) as n_imp
from mytable

Answer 1

SQL:

#normalize each subgroup 
select
 imp,
 imp/SUM(imp) Over (partition website) as n_imp
from mytable

Pandas:

df[['website','imp']].assign(n_imp=df['imp']/df.groupby('website')['imp'].transform('sum'))