用于更复杂的sql查询的pandas语法

Question

我正在寻找熊猫语法来完成以下聚合到Pandas DataFrame。我无法找到一个例子来说明如何在pandas中完成以下sql查询。

#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 

熊猫：

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

Answer 2

大熊猫具有功能read_sql，让你在写SQL查询和结果拉成数据帧的。