python - 乘法追加python

Question

我有一个 Pandas 数据框

   Colour   Type    Cost    Price   Type
0  Red      Car     3        5       Standard
1  Blue     Bike    6        7       Standard
2  Blue     Car     4        8       Standard
3  Green    Bike    6        9       Standard
4   Yellow  Bike    3        3       Standard

然后我有一个调整系列，我想将其乘以成本并添加到底部

Red   2
Blue  1
Green 3

所以输出是:

   Colour   Type    Cost    Price   Type
0  Red      Car     3        5       Standard
1  Blue     Bike    6        7       Standard
2  Blue     Car     4        8       Standard
3  Green    Bike    6        9       Standard
4   Yellow  Bike    3        3       Standard
0  Red      Car     6        10       Adjusted
1  Blue     Bike    6        7       Adjusted
2  Blue     Car     4        8       Adjusted
3  Green    Bike    18        27       Adjusted

我有点迷茫，有没有一种简单的方法可以做到这一点？

Answer 1

您可以使用merge 和concat。

调整数据框:

   Colour   value
0   Red     2
1   Blue    1
2   Green   3

然后:

temp = df.merge(adj)

temp["Cost"] = temp["Cost"]*temp["value"]
temp["Price"] = temp["Price"]*temp["value"]
temp["Type.1"] = ["Adjusted"]*temp.shape[0]


pd.concat([df, temp.iloc[:,0:5]], axis=0)

输出:

    Colour  Type    Cost    Price   Type.1
0   Red     Car     3   5   Standard
1   Blue    Bike    6   7   Standard
2   Blue    Car     4   8   Standard
3   Green   Bike    6   9   Standard
4   Yellow  Bike    3   3   Standard
0   Red     Car     6   10  Adjusted
1   Blue    Bike    6   7   Adjusted
2   Blue    Car     4   8   Adjusted
3   Green   Bike    18  27  Adjusted