如何在python中遍历数据框中的一列，得到该行对应的算术计算

Question

Data Frame:(small data frame provided) (actual data frame is large)数据框：（提供小数据框）（实际数据框很大）

using above data frame calculations to be done:使用上述数据框计算来完成：

Baking Goods = [(4.880 * 5) + (4.920 * 5) + (5.260 * 5) + (5.425 * 3)]烘焙食品 = [(4.880 * 5) + (4.920 * 5) + (5.260 * 5) + (5.425 * 3)]
= (24.4 + 24.6 + 26.3 + 16.275)/(18) = (24.4 + 24.6 + 26.3 + 16.275)/(18)
Breads =[(5.035 * 2)+(5.260 * 2)]面包=[(5.035 * 2)+(5.260 * 2)]

[same calculation as 1) according to data frame] [根据数据框计算与1)相同]

[same calculation as 1) according to data frame] [根据数据框计算与1)相同]

Answer 1

I think you need multiple values and then aggregate sum like:我认为您需要多个值，然后汇总总和，例如：

df = df.assign(new = df['Item Weight'].mul(df['grp cnt'])).groupby('Item Type')['new'].sum()

Answer 2

try using groupby and then apply .尝试使用groupby然后apply 。

df = df.groupby('Item Type').apply(lambda x: x.prod(axis=1).sum()/x['grp cnt'].sum())

OR或者

x = df.set_index('Item Type')
df = x.prod(axis=1).groupby('Item Type').sum().div(x.groupby('Item Type')['grp cnt'].sum())

df:东风：

Item Type
Baking Goods    5.087500
Breads          5.110000
Breakfast       7.967187
dtype: float64