Pandas:如何对来自传入列表的多个列执行相同的计算?

Question

给定下面的代码，我想计算三个额外的列，称为&;Expected Sales {letter}&;将A、B和C的每一列乘以价格列。但是要做到这一点，我想传递一个列名列表，这样只有那些在列名中带有"Group"的列名才会相乘(这意味着其他什么都不做)

data = [(3,5,7), (2,4,6), (5,8,9.2)]
df = pd.DataFrame(data, columns = ['Group A','Group B','Group C'])
df['Fruit'] = ('apples', 'bananas', 'pears')
df['Price'] = (1, 0.5, 2)
df['Other'] = ("blah1", "blah2", "blah3")

Answer 1

使用filter来选择列，然后使用rename来替换"Group"string by "Expected Sales"

df1 = (df.filter(like='Group').mul(df['Price'], axis=0)
.rename(columns=lambda x: x.replace('Group', 'Expected Sales')))
out = pd.concat([df, df1], axis=1)

输出:

>>> out
Group A  Group B  Group C    Fruit  Price  Other  Expected Sales A  Expected Sales B  Expected Sales C
0        3        5      7.0   apples    1.0  blah1               3.0               5.0               7.0
1        2        4      6.0  bananas    0.5  blah2               1.0               2.0               3.0
2        5        8      9.2    pears    2.0  blah3              10.0              16.0              18.4