Python/Pandas - 计算比率

Question

我有这个数据框:

bal:

             year   id   unit period          Revenues  Ativo Não-Circulante  \
business_id                                                                    
9564         2012  302  dsada  anual        5964168.52           10976013.70   
9564         2011  303  dsada  anual        5774707.15           10867868.13   
2361         2013  304  dsada  anual        3652575.31            6608468.52   
2361         2012  305  dsada  anual         321076.15            6027066.03   
2361         2011  306  dsada  anual        3858137.49            9733126.02   
2369         2012  307  dsada  anual         351373.66            9402830.89   
8104         2012  308  dsada  anual        3503226.02            6267307.01 
...

我想创建一个名为“Growth”的列。这将是:

(今年收入/去年收入)- 1

数据框应如下所示:

             year   id   unit period          Revenues               Growth  \
business_id                                                                    
9564         2012  302  dsada  anual        5964168.52                0.0328   
9564         2011  303  dsada  anual        5774707.15                   NaN   
2361         2013  304  dsada  anual        3652575.31                 10.37   
2361         2012  305  dsada  anual         321076.15                 -0.91   
2361         2011  306  dsada  anual        3858137.49                   NaN   
2369         2012  307  dsada  anual         351373.66                   NaN   
8104         2012  308  dsada  anual        3503226.02                   NaN 
...

我怎样才能做到这一点？

Answer 1

我假设您的数据框名为df。首先休息索引，使 business_id 成为一列，然后按 year 对结果进行排序。现在，根据 business_id 对数据帧进行分组，并转换结果以获得收入的百分比变化。最后利用索引得到原始顺序。

df2 = df.reset_index().sort_values(['year'])
df2 = (
    df2
    .assign(Growth=df2.groupby(['business_id'])['Revenues'].transform(
        lambda group: group.pct_change()))
    .sort_index()
)
>>> df2
business_id year    id  unit    period  Revenues    Ativo Não-Circulante    Growth
0   9564    2012    302 dsada   anual   5964168.52  10976013.70           0.032809
1   9564    2011    303 dsada   anual   5774707.15  10867868.13                NaN
2   2361    2013    304 dsada   anual   3652575.31  6608468.52           10.376041
3   2361    2012    305 dsada   anual   321076.15   6027066.03           -0.916779
4   2361    2011    306 dsada   anual   3858137.49  9733126.02                 NaN
5   2369    2012    307 dsada   anual   351373.66   9402830.89                 NaN
6   8104    2012    308 dsada   anual   3503226.02  6267307.01                 NaN

我认为您的预期输出有错误:

5964168.52 / 5774707.15 - 1 = 0.0328  # vs. 0.16 shown.