Error When Calling A Groupby Object Inside A Pandas DataFrame

I've got this dataframe: person_code #CNAE growth size 0 231 32 0.54 32 1 233 43 0.12 333 2 432 32 0.44 2

Solution 1:

There is one way, convert a to dict , then map it back

#a=df.groupby('#CNAE',group_keys=False).apply(pd.DataFrame.nlargest,n=3,columns='growth')
df['top3growth']=df['#CNAE'].map(a.groupby('#CNAE').apply(lambda x : x.to_dict()))
df
Out[195]: 
   person_code  #CNAE  growth  size  \
0          231     32    0.54    32   
1          233     43    0.12   333   
2          432     32    0.44    21   
3          431     56    0.32    23   
4          654     89    0.12    89   
5          764     32    0.20   211   
6          434     32    0.82    90   
                                          top3growth  
0  {'person_code': {0: 231, 2: 432, 6: 434}, 'gro...  
1  {'person_code': {1: 233}, 'growth': {1: 0.12},...  
2  {'person_code': {0: 231, 2: 432, 6: 434}, 'gro...  
3  {'person_code': {3: 431}, 'growth': {3: 0.32},...  
4  {'person_code': {4: 654}, 'growth': {4: 0.12},...  
5  {'person_code': {0: 231, 2: 432, 6: 434}, 'gro...  
6  {'person_code': {0: 231, 2: 432, 6: 434}, 'gro...  

After create your new column , if you want to convert the single cell back to dataframe

pd.DataFrame(df.top3growth[0])
Out[197]: 
   #CNAE  growth  person_code  size
0     32    0.54          231    32
2     32    0.44          432    21
6     32    0.82          434    90