python 中 pivot 表中的总值

Question

My original dataframe is similar to the one below:

df= pd.DataFrame({'Variation' : ['A']*5 + ['B']*3 + ['A']*4, 
                  'id': [11]*4 + [12] + [15]*2 + [17] + [20]*4,
                 'steps' : ['start','step1','step2','end','end','step1','step2','step1','start','step1','step2','end']})

I wanted to create a pivot table from this dataframe for which I have used the below mentioned code:

df1=df.pivot_table(index=['Variation'], columns=['steps'], 
                          values='id', aggfunc='count', fill_value=0)

However, I also wanted to look at the total distinct count of the id's as well. Can someone please let me know how to achieve this? My expected output should be:

| Variation | Total id | Total start | Total step1 | Total step2 | Total end |
|-----------|----------|-------------|-------------|-------------|-----------|
| A         | 3        | 2           | 2           | 2           | 3         |
| B         | 2        | 0           | 2           | 1           | 0         |

Answer 1

Use SeriesGroupBy.nunique :

df1 = df1.join(df.groupby('Variation')['id'].nunique().rename('Total id'))
print(df1)
           end  start  step1  step2  Total id
Variation                                    
A            3      2      2      2         3
B            0      0      2      1         2

If need column after Variation :

c = ['id'] + df['steps'].unique().tolist()
df1 = (df1.join(df.groupby('Variation')['id'].nunique())
          .reindex(columns=c)
          .add_prefix('Total ')
          .reset_index()
          .rename_axis(None, axis=1))

print(df1)
  Variation  Total id  Total start  Total step1  Total step2  Total end
0         A         3            2            2            2          3
1         B         2            0            2            1          0